21613615106 has 4 divisors (see below), whose sum is σ = 32420422662. Its totient is φ = 10806807552.

The previous prime is 21613615103. The next prime is 21613615139. The reversal of 21613615106 is 60151631612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 18250659025 + 3362956081 = 135095^2 + 57991^2 .

It is a super-2 number, since 2×21613615106² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21613615103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5403403775 + ... + 5403403778.

Almost surely, 2^21613615106 is an apocalyptic number.

21613615106 is a deficient number, since it is larger than the sum of its proper divisors (10806807556).

21613615106 is a wasteful number, since it uses less digits than its factorization.

21613615106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10806807555.

The product of its (nonzero) digits is 6480, while the sum is 32.

The spelling of 21613615106 in words is "twenty-one billion, six hundred thirteen million, six hundred fifteen thousand, one hundred six".