21319256 has 48 divisors (see below), whose sum is σ = 47028240. Its totient is φ = 8873280.

The previous prime is 21319223. The next prime is 21319261. The reversal of 21319256 is 65291312.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 269825 + ... + 269903.

It is an arithmetic number, because the mean of its divisors is an integer number (979755).

Almost surely, 2^21319256 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 21319256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23514120).

21319256 is an abundant number, since it is smaller than the sum of its proper divisors (25708984).

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

21319256 is an equidigital number, since it uses as much as digits as its factorization.

21319256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 149 counting only the distinct ones).

The product of its digits is 3240, while the sum is 29.

The square root of 21319256 is about 4617.2779860000. The cubic root of 21319256 is about 277.2834920808.

The spelling of 21319256 in words is "twenty-one million, three hundred nineteen thousand, two hundred fifty-six".