21874320 has 320 divisors, whose sum is σ = 87494400. Its totient is φ = 4976640.

The previous prime is 21874297. The next prime is 21874327. The reversal of 21874320 is 2347812.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21874327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 533500 + ... + 533540.

It is an arithmetic number, because the mean of its divisors is an integer number (273420).

Almost surely, 2^21874320 is an apocalyptic number.

21874320 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 21874320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43747200).

21874320 is an abundant number, since it is smaller than the sum of its proper divisors (65620080).

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

21874320 is a wasteful number, since it uses less digits than its factorization.

21874320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21874320 is about 4676.9990378447. Note that the first 3 decimals coincide. The cubic root of 21874320 is about 279.6693375533.

The spelling of 21874320 in words is "twenty-one million, eight hundred seventy-four thousand, three hundred twenty".