20642464 has 12 divisors (see below), whose sum is σ = 40639914. Its totient is φ = 10321216.

The previous prime is 20642449. The next prime is 20642467. The reversal of 20642464 is 46424602.

It can be written as a sum of positive squares in only one way, i.e., 13395600 + 7246864 = 3660^2 + 2692^2 .

It is a super-2 number, since 2×20642464² = 852222639982592, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20642467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322507 + ... + 322570.

Almost surely, 2^20642464 is an apocalyptic number.

It is an amenable number.

20642464 is a deficient number, since it is larger than the sum of its proper divisors (19997450).

20642464 is an equidigital number, since it uses as much as digits as its factorization.

20642464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645087 (or 645079 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 20642464 is about 4543.3978474265. The cubic root of 20642464 is about 274.3177091480.

The spelling of 20642464 in words is "twenty million, six hundred forty-two thousand, four hundred sixty-four".