21874860 has 144 divisors (see below), whose sum is σ = 78763776. Its totient is φ = 4992192.

The previous prime is 21874843. The next prime is 21874891. The reversal of 21874860 is 6847812.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 33699 + ... + 34341.

Almost surely, 2^21874860 is an apocalyptic number.

21874860 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21874860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39381888).

21874860 is an abundant number, since it is smaller than the sum of its proper divisors (56888916).

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

21874860 is a wasteful number, since it uses less digits than its factorization.

21874860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 674 (or 660 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 21874860 is about 4677.0567668139. The cubic root of 21874860 is about 279.6716388850.

It can be divided in two parts, 218 and 74860, that added together give a triangular number (75078 = T₃₈₇).

The spelling of 21874860 in words is "twenty-one million, eight hundred seventy-four thousand, eight hundred sixty".