20615618688 has 192 divisors, whose sum is σ = 65256801120. Its totient is φ = 5746298880.

The previous prime is 20615618677. The next prime is 20615618731. The reversal of 20615618688 is 88681651602.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (192).

It is a self number, because there is not a number n which added to its sum of digits gives 20615618688.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 758095 + ... + 784817.

Almost surely, 2^20615618688 is an apocalyptic number.

20615618688 is a gapful number since it is divisible by the number (28) 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 20615618688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32628400560).

20615618688 is an abundant number, since it is smaller than the sum of its proper divisors (44641182432).

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

20615618688 is a wasteful number, since it uses less digits than its factorization.

20615618688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26795 (or 26776 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 51.

The spelling of 20615618688 in words is "twenty billion, six hundred fifteen million, six hundred eighteen thousand, six hundred eighty-eight".