21893756 has 24 divisors (see below), whose sum is σ = 40720176. Its totient is φ = 10264320.

The previous prime is 21893749. The next prime is 21893759. The reversal of 21893756 is 65739812.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21893759) 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, 26591 + ... + 27401.

It is an arithmetic number, because the mean of its divisors is an integer number (1696674).

Almost surely, 2^21893756 is an apocalyptic number.

It is an amenable number.

21893756 is a deficient number, since it is larger than the sum of its proper divisors (18826420).

21893756 is a wasteful number, since it uses less digits than its factorization.

21893756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1229 (or 1227 counting only the distinct ones).

The product of its digits is 90720, while the sum is 41.

The square root of 21893756 is about 4679.0764045910. The cubic root of 21893756 is about 279.7521446093.

The spelling of 21893756 in words is "twenty-one million, eight hundred ninety-three thousand, seven hundred fifty-six".