20664693 has 32 divisors (see below), whose sum is σ = 36126720. Its totient is φ = 11424240.

The previous prime is 20664689. The next prime is 20664727. The reversal of 20664693 is 39646602.

20664693 is a `hidden beast` number, since 2 + 0 + 6 + 646 + 9 + 3 = 666.

It is not a de Polignac number, because 20664693 - 2² = 20664689 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664653) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4096 + ... + 7622.

It is an arithmetic number, because the mean of its divisors is an integer number (1128960).

Almost surely, 2^20664693 is an apocalyptic number.

It is an amenable number.

20664693 is a deficient number, since it is larger than the sum of its proper divisors (15462027).

20664693 is a wasteful number, since it uses less digits than its factorization.

20664693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3574 (or 3568 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 20664693 is about 4545.8434860870. The cubic root of 20664693 is about 274.4161408863.

The spelling of 20664693 in words is "twenty million, six hundred sixty-four thousand, six hundred ninety-three".