20636664 has 16 divisors (see below), whose sum is σ = 51591720. Its totient is φ = 6878880.

The previous prime is 20636621. The next prime is 20636683. The reversal of 20636664 is 46663602.

It is a congruent number.

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, 429907 + ... + 429954.

Almost surely, 2^20636664 is an apocalyptic number.

20636664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20636664 is an abundant number, since it is smaller than the sum of its proper divisors (30955056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20636664 is a wasteful number, since it uses less digits than its factorization.

20636664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859870 (or 859866 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 20636664 is about 4542.7595137757. The cubic root of 20636664 is about 274.2920146742.

The spelling of 20636664 in words is "twenty million, six hundred thirty-six thousand, six hundred sixty-four".