21516156532 has 12 divisors (see below), whose sum is σ = 40549679716. Its totient is φ = 9930533760.

The previous prime is 21516156517. The next prime is 21516156581. The reversal of 21516156532 is 23565161512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4733990416 + 16782166116 = 68804^2 + 129546^2 .

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21516156491 and 21516156500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206886069 + ... + 206886172.

Almost surely, 2^21516156532 is an apocalyptic number.

It is an amenable number.

21516156532 is a deficient number, since it is larger than the sum of its proper divisors (19033523184).

21516156532 is a wasteful number, since it uses less digits than its factorization.

21516156532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413772258 (or 413772256 counting only the distinct ones).

The product of its digits is 54000, while the sum is 37.

The spelling of 21516156532 in words is "twenty-one billion, five hundred sixteen million, one hundred fifty-six thousand, five hundred thirty-two".