21259968 has 28 divisors (see below), whose sum is σ = 56250840. Its totient is φ = 7086592.

The previous prime is 21259967. The next prime is 21260003. The reversal of 21259968 is 86995212.

It is a super-2 number, since 2×21259968² = 903972478722048, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21259961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55173 + ... + 55556.

Almost surely, 2^21259968 is an apocalyptic number.

It is an amenable number.

21259968 is an abundant number, since it is smaller than the sum of its proper divisors (34990872).

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

21259968 is a wasteful number, since it uses less digits than its factorization.

21259968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110744 (or 110734 counting only the distinct ones).

The product of its digits is 77760, while the sum is 42.

The square root of 21259968 is about 4610.8532832872. The cubic root of 21259968 is about 277.0262153331.

The spelling of 21259968 in words is "twenty-one million, two hundred fifty-nine thousand, nine hundred sixty-eight".