20664231 has 24 divisors (see below), whose sum is σ = 33940080. Its totient is φ = 11112192.

The previous prime is 20664139. The next prime is 20664239. The reversal of 20664231 is 13246602.

It is not a de Polignac number, because 20664231 - 2⁹ = 20663719 is a prime.

It is a super-2 number, since 2×20664231² = 854020885642722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664239) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1636 + ... + 6633.

It is an arithmetic number, because the mean of its divisors is an integer number (1414170).

Almost surely, 2^20664231 is an apocalyptic number.

20664231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20664231 is a deficient number, since it is larger than the sum of its proper divisors (13275849).

20664231 is a wasteful number, since it uses less digits than its factorization.

20664231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8303 (or 8296 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 20664231 is about 4545.7926701512. The cubic root of 20664231 is about 274.4140958329.

The spelling of 20664231 in words is "twenty million, six hundred sixty-four thousand, two hundred thirty-one".