20664831 has 8 divisors (see below), whose sum is σ = 30057984. Its totient is φ = 12524120.

The previous prime is 20664829. The next prime is 20664851. The reversal of 20664831 is 13846602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20664831 - 2¹ = 20664829 is a prime.

It is a super-2 number, since 2×20664831² = 854070480517122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20664851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 313071 + ... + 313136.

It is an arithmetic number, because the mean of its divisors is an integer number (3757248).

Almost surely, 2^20664831 is an apocalyptic number.

20664831 is a deficient number, since it is larger than the sum of its proper divisors (9393153).

20664831 is a wasteful number, since it uses less digits than its factorization.

20664831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 626221.

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 20664831 is about 4545.8586647629. The cubic root of 20664831 is about 274.4167517405.

The spelling of 20664831 in words is "twenty million, six hundred sixty-four thousand, eight hundred thirty-one".