20581610916 has 12 divisors (see below), whose sum is σ = 48023758832. Its totient is φ = 6860536968.

The previous prime is 20581610899. The next prime is 20581610981. The reversal of 20581610916 is 61901618502.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×20581610916² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 857567110 + ... + 857567133.

Almost surely, 2^20581610916 is an apocalyptic number.

It is an amenable number.

20581610916 is an abundant number, since it is smaller than the sum of its proper divisors (27442147916).

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

20581610916 is a wasteful number, since it uses less digits than its factorization.

20581610916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1715134250 (or 1715134248 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 39.

The spelling of 20581610916 in words is "twenty billion, five hundred eighty-one million, six hundred ten thousand, nine hundred sixteen".