20309667840 has 1248 divisors, whose sum is σ = 92737322496. Its totient is φ = 4140564480.

The previous prime is 20309667839. The next prime is 20309667841. The reversal of 20309667840 is 4876690302.

It is an interprime number because it is at equal distance from previous prime (20309667839) and next prime (20309667841).

It is a super-2 number, since 2×20309667840² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309667841) 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 95 ways as a sum of consecutive naturals, for example, 383201254 + ... + 383201306.

It is an arithmetic number, because the mean of its divisors is an integer number (74308752).

Almost surely, 2^20309667840 is an apocalyptic number.

20309667840 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 20309667840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46368661248).

20309667840 is an abundant number, since it is smaller than the sum of its proper divisors (72427654656).

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

20309667840 is an equidigital number, since it uses as much as digits as its factorization.

20309667840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 20309667840 in words is "twenty billion, three hundred nine million, six hundred sixty-seven thousand, eight hundred forty".