21479880 has 64 divisors (see below), whose sum is σ = 67838400. Its totient is φ = 5425920.

The previous prime is 21479873. The next prime is 21479881. The reversal of 21479880 is 8897412.

It is a super-2 number, since 2×21479880² = 922770489628800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21479881) 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 15 ways as a sum of consecutive naturals, for example, 2431 + ... + 6990.

It is an arithmetic number, because the mean of its divisors is an integer number (1059975).

Almost surely, 2^21479880 is an apocalyptic number.

21479880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21479880 is an abundant number, since it is smaller than the sum of its proper divisors (46358520).

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

21479880 is a wasteful number, since it uses less digits than its factorization.

21479880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9454 (or 9450 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 21479880 is about 4634.6391445289. The cubic root of 21479880 is about 277.9781222540.

The spelling of 21479880 in words is "twenty-one million, four hundred seventy-nine thousand, eight hundred eighty".