20972736 has 112 divisors (see below), whose sum is σ = 63093600. Its totient is φ = 6829056.

The previous prime is 20972729. The next prime is 20972741. The reversal of 20972736 is 63727902.

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 20972736.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91470 + ... + 91698.

Almost surely, 2^20972736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20972736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31546800).

20972736 is an abundant number, since it is smaller than the sum of its proper divisors (42120864).

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

20972736 is a wasteful number, since it uses less digits than its factorization.

20972736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 287 counting only the distinct ones).

The product of its (nonzero) digits is 31752, while the sum is 36.

The square root of 20972736 is about 4579.5999825312. The cubic root of 20972736 is about 275.7729702027.

The spelling of 20972736 in words is "twenty million, nine hundred seventy-two thousand, seven hundred thirty-six".