21237297 has 12 divisors (see below), whose sum is σ = 29108016. Its totient is φ = 13772880.

The previous prime is 21237289. The next prime is 21237311. The reversal of 21237297 is 79273212.

It is not a de Polignac number, because 21237297 - 2³ = 21237289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21237217) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1522 + ... + 6692.

It is an arithmetic number, because the mean of its divisors is an integer number (2425668).

Almost surely, 2^21237297 is an apocalyptic number.

It is an amenable number.

21237297 is a deficient number, since it is larger than the sum of its proper divisors (7870719).

21237297 is an equidigital number, since it uses as much as digits as its factorization.

21237297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5248 (or 5211 counting only the distinct ones).

The product of its digits is 10584, while the sum is 33.

The square root of 21237297 is about 4608.3941888688. The cubic root of 21237297 is about 276.9277094607.

The spelling of 21237297 in words is "twenty-one million, two hundred thirty-seven thousand, two hundred ninety-seven".