21254256 has 60 divisors (see below), whose sum is σ = 60101808. Its totient is φ = 7011072.

The previous prime is 21254249. The next prime is 21254263. The reversal of 21254256 is 65245212.

It is an interprime number because it is at equal distance from previous prime (21254249) and next prime (21254263).

It is a super-2 number, since 2×21254256² = 903486796227072, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14116 + ... + 15548.

Almost surely, 2^21254256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21254256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30050904).

21254256 is an abundant number, since it is smaller than the sum of its proper divisors (38847552).

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

21254256 is a wasteful number, since it uses less digits than its factorization.

21254256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1550 (or 1541 counting only the distinct ones).

The product of its digits is 4800, while the sum is 27.

The square root of 21254256 is about 4610.2338335490. The cubic root of 21254256 is about 277.0014031998.

Adding to 21254256 its reverse (65245212), we get a palindrome (86499468).

The spelling of 21254256 in words is "twenty-one million, two hundred fifty-four thousand, two hundred fifty-six".