21251168 has 12 divisors (see below), whose sum is σ = 41838300. Its totient is φ = 10625568.

The previous prime is 21251141. The next prime is 21251179. The reversal of 21251168 is 86115212.

It is a super-2 number, since 2×21251168² = 903224282728448, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332018 + ... + 332081.

It is an arithmetic number, because the mean of its divisors is an integer number (3486525).

Almost surely, 2^21251168 is an apocalyptic number.

It is an amenable number.

21251168 is a deficient number, since it is larger than the sum of its proper divisors (20587132).

21251168 is an equidigital number, since it uses as much as digits as its factorization.

21251168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664109 (or 664101 counting only the distinct ones).

The product of its digits is 960, while the sum is 26.

The square root of 21251168 is about 4609.8989142930. The cubic root of 21251168 is about 276.9879875062.

The spelling of 21251168 in words is "twenty-one million, two hundred fifty-one thousand, one hundred sixty-eight".