20507621564 has 6 divisors (see below), whose sum is σ = 35888337744. Its totient is φ = 10253810780.

The previous prime is 20507621503. The next prime is 20507621567. The reversal of 20507621564 is 46512670502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20507621567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2563452692 + ... + 2563452699.

It is an arithmetic number, because the mean of its divisors is an integer number (5981389624).

Almost surely, 2^20507621564 is an apocalyptic number.

It is an amenable number.

20507621564 is a deficient number, since it is larger than the sum of its proper divisors (15380716180).

20507621564 is a wasteful number, since it uses less digits than its factorization.

20507621564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5126905395 (or 5126905393 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 38.

The spelling of 20507621564 in words is "twenty billion, five hundred seven million, six hundred twenty-one thousand, five hundred sixty-four".