21874440 has 64 divisors (see below), whose sum is σ = 75000960. Its totient is φ = 4999680.

The previous prime is 21874421. The next prime is 21874451. The reversal of 21874440 is 4447812.

It is a super-2 number, since 2×21874440² = 956982250627200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21874398 and 21874407.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 12181 + ... + 13860.

It is an arithmetic number, because the mean of its divisors is an integer number (1171890).

Almost surely, 2^21874440 is an apocalyptic number.

21874440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21874440 is an abundant number, since it is smaller than the sum of its proper divisors (53126520).

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

21874440 is a wasteful number, since it uses less digits than its factorization.

21874440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26062 (or 26058 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 30.

The square root of 21874440 is about 4677.0118665661. The cubic root of 21874440 is about 279.6698489636.

The spelling of 21874440 in words is "twenty-one million, eight hundred seventy-four thousand, four hundred forty".