20664810644 has 12 divisors (see below), whose sum is σ = 37735741344. Its totient is φ = 9883170264.

The previous prime is 20664810559. The next prime is 20664810679. The reversal of 20664810644 is 44601846602.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 112308662 + ... + 112308845.

It is an arithmetic number, because the mean of its divisors is an integer number (3144645112).

Almost surely, 2^20664810644 is an apocalyptic number.

It is an amenable number.

20664810644 is a deficient number, since it is larger than the sum of its proper divisors (17070930700).

20664810644 is a wasteful number, since it uses less digits than its factorization.

20664810644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224617534 (or 224617532 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 41.

The spelling of 20664810644 in words is "twenty billion, six hundred sixty-four million, eight hundred ten thousand, six hundred forty-four".