21395943522 has 54 divisors (see below), whose sum is σ = 48493421067. Its totient is φ = 6817344072.

The previous prime is 21395943509. The next prime is 21395943551. The reversal of 21395943522 is 22534959312.

21395943522 is a `hidden beast` number, since 2 + 1 + 3 + 9 + 594 + 3 + 52 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10697971761 + 10697971761 = 103431^2 + 103431^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103431.

It is a super-2 number, since 2×21395943522² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 14272729 + ... + 14274227.

Almost surely, 2^21395943522 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21395943522

21395943522 is an abundant number, since it is smaller than the sum of its proper divisors (27097477545).

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

21395943522 is an equidigital number, since it uses as much as digits as its factorization.

21395943522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3052 (or 1527 counting only the distinct ones).

The product of its digits is 583200, while the sum is 45.

The spelling of 21395943522 in words is "twenty-one billion, three hundred ninety-five million, nine hundred forty-three thousand, five hundred twenty-two".