21867936 has 72 divisors (see below), whose sum is σ = 60679584. Its totient is φ = 6894720.

The previous prime is 21867931. The next prime is 21867941. The reversal of 21867936 is 63976812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21867931) and next prime (21867941).

It is not an unprimeable number, because it can be changed into a prime (21867931) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34341 + ... + 34971.

It is an arithmetic number, because the mean of its divisors is an integer number (842772).

Almost surely, 2^21867936 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 21867936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30339792).

21867936 is an abundant number, since it is smaller than the sum of its proper divisors (38811648).

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

21867936 is a wasteful number, since it uses less digits than its factorization.

21867936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682 (or 655 counting only the distinct ones).

The product of its digits is 108864, while the sum is 42.

The square root of 21867936 is about 4676.3164991262. The cubic root of 21867936 is about 279.6421278271.

The spelling of 21867936 in words is "twenty-one million, eight hundred sixty-seven thousand, nine hundred thirty-six".