21995256 has 16 divisors (see below), whose sum is σ = 54988200. Its totient is φ = 7331744.

The previous prime is 21995243. The next prime is 21995287. The reversal of 21995256 is 65259912.

It is a super-3 number, since 3×21995256³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 458211 + ... + 458258.

Almost surely, 2^21995256 is an apocalyptic number.

It is an amenable number.

21995256 is an abundant number, since it is smaller than the sum of its proper divisors (32992944).

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

21995256 is a wasteful number, since it uses less digits than its factorization.

21995256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 916478 (or 916474 counting only the distinct ones).

The product of its digits is 48600, while the sum is 39.

The square root of 21995256 is about 4689.9100204588. The cubic root of 21995256 is about 280.1837908986.

The spelling of 21995256 in words is "twenty-one million, nine hundred ninety-five thousand, two hundred fifty-six".