21613312775506 has 8 divisors (see below), whose sum is σ = 32456768222844. Its totient is φ = 10794390034560.

The previous prime is 21613312775491. The next prime is 21613312775591. The reversal of 21613312775506 is 60557721331612.

It can be written as a sum of positive squares in 2 ways, for example, as 16565836113225 + 5047476662281 = 4070115^2 + 2246659^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×21613312775506³ (a number of 41 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21613312775506.

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, 6133174395 + ... + 6133177918.

Almost surely, 2^{21613312775506} is an apocalyptic number.

21613312775506 is a deficient number, since it is larger than the sum of its proper divisors (10843455447338).

21613312775506 is a wasteful number, since it uses less digits than its factorization.

21613312775506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12266353196.

The product of its (nonzero) digits is 1587600, while the sum is 49.

The spelling of 21613312775506 in words is "twenty-one trillion, six hundred thirteen billion, three hundred twelve million, seven hundred seventy-five thousand, five hundred six".