18616878617 has 2 divisors, whose sum is σ = 18616878618. Its totient is φ = 18616878616.

The previous prime is 18616878613. The next prime is 18616878667. The reversal of 18616878617 is 71687861681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17901369616 + 715509001 = 133796^2 + 26749^2 .

It is a cyclic number.

It is not a de Polignac number, because 18616878617 - 2² = 18616878613 is a prime.

It is a super-3 number, since 3×18616878617³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (18616878613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9308439308 + 9308439309.

It is an arithmetic number, because the mean of its divisors is an integer number (9308439309).

Almost surely, 2^18616878617 is an apocalyptic number.

It is an amenable number.

18616878617 is a deficient number, since it is larger than the sum of its proper divisors (1).

18616878617 is an equidigital number, since it uses as much as digits as its factorization.

18616878617 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5419008, while the sum is 59.

The spelling of 18616878617 in words is "eighteen billion, six hundred sixteen million, eight hundred seventy-eight thousand, six hundred seventeen".