21612451752 has 80 divisors (see below), whose sum is σ = 60806739840. Its totient is φ = 7171797024.

The previous prime is 21612451741. The next prime is 21612451799. The reversal of 21612451752 is 25715421612.

21612451752 is a `hidden beast` number, since 2 + 16 + 124 + 517 + 5 + 2 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 69723 + ... + 219285.

It is an arithmetic number, because the mean of its divisors is an integer number (760084248).

Almost surely, 2^21612451752 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 21612451752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30403369920).

21612451752 is an abundant number, since it is smaller than the sum of its proper divisors (39194288088).

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

21612451752 is a wasteful number, since it uses less digits than its factorization.

21612451752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149804 (or 149791 counting only the distinct ones).

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

The spelling of 21612451752 in words is "twenty-one billion, six hundred twelve million, four hundred fifty-one thousand, seven hundred fifty-two".