20565477764 has 12 divisors (see below), whose sum is σ = 38758015884. Its totient is φ = 9491758944.

The previous prime is 20565477739. The next prime is 20565477781. The reversal of 20565477764 is 46777456502.

It can be written as a sum of positive squares in 2 ways, for example, as 10128812164 + 10436665600 = 100642^2 + 102160^2 .

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, 197744927 + ... + 197745030.

It is an arithmetic number, because the mean of its divisors is an integer number (3229834657).

Almost surely, 2^20565477764 is an apocalyptic number.

It is an amenable number.

20565477764 is a deficient number, since it is larger than the sum of its proper divisors (18192538120).

20565477764 is a wasteful number, since it uses less digits than its factorization.

20565477764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395489974 (or 395489972 counting only the distinct ones).

The product of its (nonzero) digits is 9878400, while the sum is 53.

The spelling of 20565477764 in words is "twenty billion, five hundred sixty-five million, four hundred seventy-seven thousand, seven hundred sixty-four".