20918764 has 24 divisors (see below), whose sum is σ = 37806048. Its totient is φ = 10120320.

The previous prime is 20918759. The next prime is 20918767. The reversal of 20918764 is 46781902.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (20918767) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41337 + ... + 41839.

It is an arithmetic number, because the mean of its divisors is an integer number (1575252).

Almost surely, 2^20918764 is an apocalyptic number.

It is an amenable number.

20918764 is a deficient number, since it is larger than the sum of its proper divisors (16887284).

20918764 is a wasteful number, since it uses less digits than its factorization.

20918764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 20918764 is about 4573.7035321498. The cubic root of 20918764 is about 275.5362055968.

The spelling of 20918764 in words is "twenty million, nine hundred eighteen thousand, seven hundred sixty-four".