21456337 has 12 divisors (see below), whose sum is σ = 25213440. Its totient is φ = 17886096.

The previous prime is 21456319. The next prime is 21456341. The reversal of 21456337 is 73365412.

It is not a de Polignac number, because 21456337 - 2²³ = 13067729 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21456299 and 21456308.

It is not an unprimeable number, because it can be changed into a prime (21456937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8464 + ... + 10702.

It is an arithmetic number, because the mean of its divisors is an integer number (2101120).

Almost surely, 2^21456337 is an apocalyptic number.

It is an amenable number.

21456337 is a deficient number, since it is larger than the sum of its proper divisors (3757103).

21456337 is an equidigital number, since it uses as much as digits as its factorization.

21456337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2320 (or 2283 counting only the distinct ones).

The product of its digits is 15120, while the sum is 31.

The square root of 21456337 is about 4632.0985524922. The cubic root of 21456337 is about 277.8765259167.

The spelling of 21456337 in words is "twenty-one million, four hundred fifty-six thousand, three hundred thirty-seven".