21715522416 has 160 divisors (see below), whose sum is σ = 71393287680. Its totient is φ = 6190746624.

The previous prime is 21715522403. The next prime is 21715522429. The reversal of 21715522416 is 61422551712.

21715522416 is a `hidden beast` number, since 2 + 1 + 71 + 552 + 24 + 16 = 666.

It is an interprime number because it is at equal distance from previous prime (21715522403) and next prime (21715522429).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1404520 + ... + 1419896.

It is an arithmetic number, because the mean of its divisors is an integer number (446208048).

Almost surely, 2^21715522416 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 21715522416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35696643840).

21715522416 is an abundant number, since it is smaller than the sum of its proper divisors (49677765264).

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

21715522416 is a wasteful number, since it uses less digits than its factorization.

21715522416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15868 (or 15856 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The spelling of 21715522416 in words is "twenty-one billion, seven hundred fifteen million, five hundred twenty-two thousand, four hundred sixteen".