20611664 has 30 divisors (see below), whose sum is σ = 41087214. Its totient is φ = 10016640.

The previous prime is 20611649. The next prime is 20611681. The reversal of 20611664 is 46611602.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 12816400 + 7795264 = 3580^2 + 2792^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a congruent 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, 21434 + ... + 22374.

Almost surely, 2^20611664 is an apocalyptic number.

It is an amenable number.

20611664 is a deficient number, since it is larger than the sum of its proper divisors (20475550).

20611664 is an equidigital number, since it uses as much as digits as its factorization.

20611664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1023 (or 980 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20611664 is about 4540.0070484527. The cubic root of 20611664 is about 274.1812074996.

It can be divided in two parts, 206116 and 64, that multiplied together give a square (13191424 = 3632²).

The spelling of 20611664 in words is "twenty million, six hundred eleven thousand, six hundred sixty-four".