216611613 has 12 divisors (see below), whose sum is σ = 313228188. Its totient is φ = 144248640.

The previous prime is 216611561. The next prime is 216611617. The reversal of 216611613 is 316116612.

It can be written as a sum of positive squares in 2 ways, for example, as 60186564 + 156425049 = 7758^2 + 12507^2 .

It is not a de Polignac number, because 216611613 - 2²⁵ = 183057181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216611617) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4320 + ... + 21257.

It is an arithmetic number, because the mean of its divisors is an integer number (26102349).

Almost surely, 2^216611613 is an apocalyptic number.

It is an amenable number.

216611613 is a deficient number, since it is larger than the sum of its proper divisors (96616575).

216611613 is a wasteful number, since it uses less digits than its factorization.

216611613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26524 (or 26521 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 216611613 is about 14717.7312449983. The cubic root of 216611613 is about 600.5657746640.

The spelling of 216611613 in words is "two hundred sixteen million, six hundred eleven thousand, six hundred thirteen".