21715316 has 48 divisors (see below), whose sum is σ = 45964800. Its totient is φ = 8779008.

The previous prime is 21715313. The next prime is 21715321. The reversal of 21715316 is 61351712.

21715316 = T₄₈₃ + T₄₈₄ + ... + T₆₂₃.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21715313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37880 + ... + 38448.

It is an arithmetic number, because the mean of its divisors is an integer number (957600).

Almost surely, 2^21715316 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 21715316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22982400).

21715316 is an abundant number, since it is smaller than the sum of its proper divisors (24249484).

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

21715316 is a wasteful number, since it uses less digits than its factorization.

21715316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 654 counting only the distinct ones).

The product of its digits is 1260, while the sum is 26.

The square root of 21715316 is about 4659.9695277974. The cubic root of 21715316 is about 278.9900520170.

The spelling of 21715316 in words is "twenty-one million, seven hundred fifteen thousand, three hundred sixteen".