21867552 has 72 divisors (see below), whose sum is σ = 71076096. Its totient is φ = 6247296.

The previous prime is 21867551. The next prime is 21867553. The reversal of 21867552 is 25576812.

It is a happy number.

21867552 is a `hidden beast` number, since 21 + 86 + 7 + 552 = 666.

It is an interprime number because it is at equal distance from previous prime (21867551) and next prime (21867553).

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21867551) 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, 3408 + ... + 7439.

It is an arithmetic number, because the mean of its divisors is an integer number (987168).

Almost surely, 2^21867552 is an apocalyptic number.

It is an amenable number.

21867552 is an abundant number, since it is smaller than the sum of its proper divisors (49208544).

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

21867552 is a wasteful number, since it uses less digits than its factorization.

21867552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10870 (or 10859 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The square root of 21867552 is about 4676.2754409893. The cubic root of 21867552 is about 279.6404909830.

The spelling of 21867552 in words is "twenty-one million, eight hundred sixty-seven thousand, five hundred fifty-two".