20405929440 has 192 divisors, whose sum is σ = 70173020736. Its totient is φ = 4954079232.

The previous prime is 20405929433. The next prime is 20405929463. The reversal of 20405929440 is 4492950402.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 433122 + ... + 477918.

It is an arithmetic number, because the mean of its divisors is an integer number (365484483).

Almost surely, 2^20405929440 is an apocalyptic number.

20405929440 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 20405929440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35086510368).

20405929440 is an abundant number, since it is smaller than the sum of its proper divisors (49767091296).

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

20405929440 is a wasteful number, since it uses less digits than its factorization.

20405929440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44901 (or 44893 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 20405929440 in words is "twenty billion, four hundred five million, nine hundred twenty-nine thousand, four hundred forty".