20615930816 has 56 divisors (see below), whose sum is σ = 44175419904. Its totient is φ = 9489392640.

The previous prime is 20615930813. The next prime is 20615930917. The reversal of 20615930816 is 61803951602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20615930813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 277121 + ... + 343551.

It is an arithmetic number, because the mean of its divisors is an integer number (788846784).

Almost surely, 2^20615930816 is an apocalyptic number.

20615930816 is a gapful number since it is divisible by the number (26) 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 20615930816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22087709952).

20615930816 is an abundant number, since it is smaller than the sum of its proper divisors (23559489088).

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

20615930816 is a wasteful number, since it uses less digits than its factorization.

20615930816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66829 (or 66819 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 41.

The spelling of 20615930816 in words is "twenty billion, six hundred fifteen million, nine hundred thirty thousand, eight hundred sixteen".