21297952 has 24 divisors (see below), whose sum is σ = 45156636. Its totient is φ = 9829632.

The previous prime is 21297949. The next prime is 21297953. The reversal of 21297952 is 25979212.

It can be written as a sum of positive squares in 2 ways, for example, as 20830096 + 467856 = 4564^2 + 684^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21297953) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 25183 + ... + 26014.

Almost surely, 2^21297952 is an apocalyptic number.

It is an amenable number.

21297952 is an abundant number, since it is smaller than the sum of its proper divisors (23858684).

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

21297952 is a wasteful number, since it uses less digits than its factorization.

21297952 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51220 (or 51212 counting only the distinct ones).

The product of its digits is 22680, while the sum is 37.

The square root of 21297952 is about 4614.9704224404. The cubic root of 21297952 is about 277.1910996089.

The spelling of 21297952 in words is "twenty-one million, two hundred ninety-seven thousand, nine hundred fifty-two".