21877324 has 54 divisors (see below), whose sum is σ = 46777164. Its totient is φ = 8925840.

The previous prime is 21877321. The next prime is 21877363. The reversal of 21877324 is 42377812.

It is a self number, because there is not a number n which added to its sum of digits gives 21877324.

It is not an unprimeable number, because it can be changed into a prime (21877321) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 103579 + ... + 103789.

Almost surely, 2^21877324 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 21877324, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23388582).

21877324 is an abundant number, since it is smaller than the sum of its proper divisors (24899840).

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

21877324 is a wasteful number, since it uses less digits than its factorization.

21877324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275 (or 243 counting only the distinct ones).

The product of its digits is 18816, while the sum is 34.

The square root of 21877324 is about 4677.3201729195. The cubic root of 21877324 is about 279.6821392957.

It can be divided in two parts, 21877 and 324, that added together give a square (22201 = 149²).

The spelling of 21877324 in words is "twenty-one million, eight hundred seventy-seven thousand, three hundred twenty-four".