21423880 has 32 divisors (see below), whose sum is σ = 48536640. Its totient is φ = 8510400.

The previous prime is 21423863. The next prime is 21423907. The reversal of 21423880 is 8832412.

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 7 ways as a sum of consecutive naturals, for example, 4267 + ... + 7813.

It is an arithmetic number, because the mean of its divisors is an integer number (1516770).

Almost surely, 2^21423880 is an apocalyptic number.

21423880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21423880 is an abundant number, since it is smaller than the sum of its proper divisors (27112760).

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

21423880 is a wasteful number, since it uses less digits than its factorization.

21423880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3709 (or 3705 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 21423880 is about 4628.5937389233. The cubic root of 21423880 is about 277.7363406042.

The spelling of 21423880 in words is "twenty-one million, four hundred twenty-three thousand, eight hundred eighty".