21137368 has 32 divisors (see below), whose sum is σ = 47266560. Its totient is φ = 8664480.

The previous prime is 21137359. The next prime is 21137371. The reversal of 21137368 is 86373112.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 6918 + ... + 9493.

It is an arithmetic number, because the mean of its divisors is an integer number (1477080).

Almost surely, 2^21137368 is an apocalyptic number.

21137368 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21137368 is an abundant number, since it is smaller than the sum of its proper divisors (26129192).

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

21137368 is a wasteful number, since it uses less digits than its factorization.

21137368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16447 (or 16443 counting only the distinct ones).

The product of its digits is 6048, while the sum is 31.

The square root of 21137368 is about 4597.5393418654. The cubic root of 21137368 is about 276.4926787877.

The spelling of 21137368 in words is "twenty-one million, one hundred thirty-seven thousand, three hundred sixty-eight".