20644264 has 16 divisors (see below), whose sum is σ = 39957120. Its totient is φ = 9989040.

The previous prime is 20644237. The next prime is 20644303. The reversal of 20644264 is 46244602.

It is a super-2 number, since 2×20644264² = 852371272203392, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41374 + ... + 41869.

It is an arithmetic number, because the mean of its divisors is an integer number (2497320).

Almost surely, 2^20644264 is an apocalyptic number.

It is an amenable number.

20644264 is a deficient number, since it is larger than the sum of its proper divisors (19312856).

20644264 is a wasteful number, since it uses less digits than its factorization.

20644264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83280 (or 83276 counting only the distinct ones).

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

The square root of 20644264 is about 4543.5959327387. The cubic root of 20644264 is about 274.3256823164.

Adding to 20644264 its reverse (46244602), we get a palindrome (66888866).

It can be divided in two parts, 2064 and 4264, that added together give a triangular number (6328 = T₁₁₂).

The spelling of 20644264 in words is "twenty million, six hundred forty-four thousand, two hundred sixty-four".