21276256 has 48 divisors (see below), whose sum is σ = 43953840. Its totient is φ = 10124800.

The previous prime is 21276209. The next prime is 21276263. The reversal of 21276256 is 65267212.

It is a congruent 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, 93615 + ... + 93841.

It is an arithmetic number, because the mean of its divisors is an integer number (915705).

Almost surely, 2^21276256 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 21276256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21976920).

21276256 is an abundant number, since it is smaller than the sum of its proper divisors (22677584).

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

21276256 is a wasteful number, since it uses less digits than its factorization.

21276256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367 (or 359 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 21276256 is about 4612.6192125516. The cubic root of 21276256 is about 277.0969437426.

The spelling of 21276256 in words is "twenty-one million, two hundred seventy-six thousand, two hundred fifty-six".