21456252216 has 128 divisors (see below), whose sum is σ = 68152320000. Its totient is φ = 6127007616.

The previous prime is 21456252203. The next prime is 21456252263. The reversal of 21456252216 is 61225265412.

21456252216 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 625 + 2 + 21 + 6 = 666.

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, 4468585 + ... + 4473383.

It is an arithmetic number, because the mean of its divisors is an integer number (532440000).

Almost surely, 2^21456252216 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 21456252216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34076160000).

21456252216 is an abundant number, since it is smaller than the sum of its proper divisors (46696067784).

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

21456252216 is a wasteful number, since it uses less digits than its factorization.

21456252216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7778 (or 7768 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The spelling of 21456252216 in words is "twenty-one billion, four hundred fifty-six million, two hundred fifty-two thousand, two hundred sixteen".