21222039636 has 48 divisors (see below), whose sum is σ = 62880119680. Its totient is φ = 6063439680.

The previous prime is 21222039617. The next prime is 21222039649. The reversal of 21222039636 is 63693022212.

It is a happy number.

21222039636 is a `hidden beast` number, since 2 + 12 + 2 + 2 + 0 + 3 + 9 + 636 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21222039636.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14034985 + ... + 14036496.

Almost surely, 2^21222039636 is an apocalyptic number.

It is an amenable number.

21222039636 is an abundant number, since it is smaller than the sum of its proper divisors (41658080044).

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

21222039636 is a wasteful number, since it uses less digits than its factorization.

21222039636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28071501 (or 28071493 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The spelling of 21222039636 in words is "twenty-one billion, two hundred twenty-two million, thirty-nine thousand, six hundred thirty-six".