21257226 has 12 divisors (see below), whose sum is σ = 46057362. Its totient is φ = 7085736.

The previous prime is 21257209. The next prime is 21257237. The reversal of 21257226 is 62275212.

It can be written as a sum of positive squares in only one way, i.e., 18071001 + 3186225 = 4251^2 + 1785^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21257226.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 590461 + ... + 590496.

Almost surely, 2^21257226 is an apocalyptic number.

21257226 is an abundant number, since it is smaller than the sum of its proper divisors (24800136).

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

21257226 is a wasteful number, since it uses less digits than its factorization.

21257226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180965 (or 1180962 counting only the distinct ones).

The product of its digits is 3360, while the sum is 27.

The square root of 21257226 is about 4610.5559317722. Note that the first 3 decimals coincide. The cubic root of 21257226 is about 277.0143050213.

The spelling of 21257226 in words is "twenty-one million, two hundred fifty-seven thousand, two hundred twenty-six".