20664197 has 16 divisors (see below), whose sum is σ = 22851072. Its totient is φ = 18600960.

The previous prime is 20664139. The next prime is 20664239. The reversal of 20664197 is 79146602.

It is a cyclic number.

It is not a de Polignac number, because 20664197 - 2¹⁰ = 20663173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20660197) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59378 + ... + 59724.

It is an arithmetic number, because the mean of its divisors is an integer number (1428192).

Almost surely, 2^20664197 is an apocalyptic number.

It is an amenable number.

20664197 is a deficient number, since it is larger than the sum of its proper divisors (2186875).

20664197 is a wasteful number, since it uses less digits than its factorization.

20664197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 20664197 is about 4545.7889304278. The cubic root of 20664197 is about 274.4139453299.

The spelling of 20664197 in words is "twenty million, six hundred sixty-four thousand, one hundred ninety-seven".