20913756 has 48 divisors (see below), whose sum is σ = 53155200. Its totient is φ = 6374592.

The previous prime is 20913719. The next prime is 20913773. The reversal of 20913756 is 65731902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5031 + ... + 8193.

It is an arithmetic number, because the mean of its divisors is an integer number (1107400).

Almost surely, 2^20913756 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 20913756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26577600).

20913756 is an abundant number, since it is smaller than the sum of its proper divisors (32241444).

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

20913756 is a wasteful number, since it uses less digits than its factorization.

20913756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3218 (or 3216 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 33.

The square root of 20913756 is about 4573.1560218300. The cubic root of 20913756 is about 275.5142158424.

The spelling of 20913756 in words is "twenty million, nine hundred thirteen thousand, seven hundred fifty-six".