21715216636 has 6 divisors (see below), whose sum is σ = 38001629120. Its totient is φ = 10857608316.

The previous prime is 21715216609. The next prime is 21715216669. The reversal of 21715216636 is 63661251712.

It is a super-2 number, since 2×21715216636² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2714402076 + ... + 2714402083.

Almost surely, 2^21715216636 is an apocalyptic number.

It is an amenable number.

21715216636 is a deficient number, since it is larger than the sum of its proper divisors (16286412484).

21715216636 is a wasteful number, since it uses less digits than its factorization.

21715216636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5428804163 (or 5428804161 counting only the distinct ones).

The product of its digits is 90720, while the sum is 40.

The spelling of 21715216636 in words is "twenty-one billion, seven hundred fifteen million, two hundred sixteen thousand, six hundred thirty-six".