21245956 has 24 divisors (see below), whose sum is σ = 38453184. Its totient is φ = 10264800.

The previous prime is 21245947. The next prime is 21245963. The reversal of 21245956 is 65954212.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16761 + ... + 17983.

It is an arithmetic number, because the mean of its divisors is an integer number (1602216).

Almost surely, 2^21245956 is an apocalyptic number.

It is an amenable number.

21245956 is a deficient number, since it is larger than the sum of its proper divisors (17207228).

21245956 is a wasteful number, since it uses less digits than its factorization.

21245956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1371 (or 1369 counting only the distinct ones).

The product of its digits is 21600, while the sum is 34.

The square root of 21245956 is about 4609.3335743901. Note that the first 3 decimals coincide. The cubic root of 21245956 is about 276.9653412305.

It can be divided in two parts, 21245 and 956, that added together give a square (22201 = 149²).

The spelling of 21245956 in words is "twenty-one million, two hundred forty-five thousand, nine hundred fifty-six".