917961611681 has 4 divisors (see below), whose sum is σ = 926540692272. Its totient is φ = 909382531092.

The previous prime is 917961611653. The next prime is 917961611701. The reversal of 917961611681 is 186116169719.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 186116169719 = 661 ⋅281567579.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-917961611681 is a prime.

It is a super-2 number, since 2×917961611681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (917961611081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4289540135 + ... + 4289540348.

It is an arithmetic number, because the mean of its divisors is an integer number (231635173068).

Almost surely, 2^917961611681 is an apocalyptic number.

It is an amenable number.

917961611681 is a deficient number, since it is larger than the sum of its proper divisors (8579080591).

917961611681 is a wasteful number, since it uses less digits than its factorization.

917961611681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8579080590.

The product of its digits is 979776, while the sum is 56.

The spelling of 917961611681 in words is "nine hundred seventeen billion, nine hundred sixty-one million, six hundred eleven thousand, six hundred eighty-one".