20406291840 has 1152 divisors, whose sum is σ = 86344876800. Its totient is φ = 4415938560.

The previous prime is 20406291833. The next prime is 20406291847. The reversal of 20406291840 is 4819260402.

20406291840 is a `hidden beast` number, since 20 + 4 + 0 + 629 + 1 + 8 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (20406291833) and next prime (20406291847).

It is a tau number, because it is divible by the number of its divisors (1152).

It is a super-3 number, since 3×20406291840³ (a number of 32 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20406291795 and 20406291804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20406291847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 304571487 + ... + 304571553.

It is an arithmetic number, because the mean of its divisors is an integer number (74952150).

Almost surely, 2^20406291840 is an apocalyptic number.

20406291840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20406291840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43172438400).

20406291840 is an abundant number, since it is smaller than the sum of its proper divisors (65938584960).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20406291840 is a wasteful number, since it uses less digits than its factorization.

20406291840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 20406291840 in words is "twenty billion, four hundred six million, two hundred ninety-one thousand, eight hundred forty".