20664275 has 6 divisors (see below), whose sum is σ = 25623732. Its totient is φ = 16531400.

The previous prime is 20664257. The next prime is 20664289. The reversal of 20664275 is 57246602.

It is not a de Polignac number, because 20664275 - 2¹⁸ = 20402131 is a prime.

It is a super-2 number, since 2×20664275² = 854024522551250, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 413261 + ... + 413310.

It is an arithmetic number, because the mean of its divisors is an integer number (4270622).

Almost surely, 2^20664275 is an apocalyptic number.

20664275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20664275 is a deficient number, since it is larger than the sum of its proper divisors (4959457).

20664275 is an equidigital number, since it uses as much as digits as its factorization.

20664275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826581 (or 826576 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 20664275 is about 4545.7975097886. The cubic root of 20664275 is about 274.4142906012.

The spelling of 20664275 in words is "twenty million, six hundred sixty-four thousand, two hundred seventy-five".