20615464688 has 80 divisors (see below), whose sum is σ = 49266846720. Its totient is φ = 8137836288.

The previous prime is 20615464687. The next prime is 20615464691. The reversal of 20615464688 is 88646451602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20615464687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 664793 + ... + 695111.

It is an arithmetic number, because the mean of its divisors is an integer number (615835584).

Almost surely, 2^20615464688 is an apocalyptic number.

20615464688 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 20615464688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24633423360).

20615464688 is an abundant number, since it is smaller than the sum of its proper divisors (28651382032).

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

20615464688 is a wasteful number, since it uses less digits than its factorization.

20615464688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30814 (or 30808 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 50.

The spelling of 20615464688 in words is "twenty billion, six hundred fifteen million, four hundred sixty-four thousand, six hundred eighty-eight".