20639736 has 48 divisors (see below), whose sum is σ = 60201960. Its totient is φ = 6350400.

The previous prime is 20639701. The next prime is 20639741. The reversal of 20639736 is 63793602.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 20639736.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 10090 + ... + 11961.

Almost surely, 2^20639736 is an apocalyptic number.

20639736 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20639736 is an abundant number, since it is smaller than the sum of its proper divisors (39562224).

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

20639736 is a wasteful number, since it uses less digits than its factorization.

20639736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22076 (or 22069 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 36.

The square root of 20639736 is about 4543.0976216674. The cubic root of 20639736 is about 274.3056244848.

The spelling of 20639736 in words is "twenty million, six hundred thirty-nine thousand, seven hundred thirty-six".