20565651616 has 24 divisors (see below), whose sum is σ = 41001145920. Its totient is φ = 10152662208.

The previous prime is 20565651583. The next prime is 20565651643. The reversal of 20565651616 is 61615656502.

It is a super-2 number, since 2×20565651616² (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, 4065046 + ... + 4070101.

It is an arithmetic number, because the mean of its divisors is an integer number (1708381080).

Almost surely, 2^20565651616 is an apocalyptic number.

It is an amenable number.

20565651616 is a deficient number, since it is larger than the sum of its proper divisors (20435494304).

20565651616 is an equidigital number, since it uses as much as digits as its factorization.

20565651616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8135236 (or 8135228 counting only the distinct ones).

The product of its (nonzero) digits is 324000, while the sum is 43.

The spelling of 20565651616 in words is "twenty billion, five hundred sixty-five million, six hundred fifty-one thousand, six hundred sixteen".