20197664523 has 36 divisors (see below), whose sum is σ = 30809021880. Its totient is φ = 13236633792.

The previous prime is 20197664507. The next prime is 20197664527. The reversal of 20197664523 is 32546679102.

20197664523 is a `hidden beast` number, since 2 + 0 + 197 + 6 + 6 + 452 + 3 = 666.

It is not a de Polignac number, because 20197664523 - 2⁴ = 20197664507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20197664527) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 361011 + ... + 413187.

Almost surely, 2^20197664523 is an apocalyptic number.

20197664523 is a deficient number, since it is larger than the sum of its proper divisors (10611357357).

20197664523 is an frugal number, since it uses more digits than its factorization.

20197664523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52260 (or 52239 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 20197664523 in words is "twenty billion, one hundred ninety-seven million, six hundred sixty-four thousand, five hundred twenty-three".