1917118607831 has 4 divisors (see below), whose sum is σ = 2190992694672. Its totient is φ = 1643244520992.

The previous prime is 1917118607809. The next prime is 1917118607857. The reversal of 1917118607831 is 1387068117191.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1917118607831 is a prime.

It is a super-2 number, since 2×1917118607831² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1917118607891) 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, 136937043410 + ... + 136937043423.

It is an arithmetic number, because the mean of its divisors is an integer number (547748173668).

Almost surely, 2^{1917118607831} is an apocalyptic number.

1917118607831 is a deficient number, since it is larger than the sum of its proper divisors (273874086841).

1917118607831 is an equidigital number, since it uses as much as digits as its factorization.

1917118607831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273874086840.

The product of its (nonzero) digits is 508032, while the sum is 53.

The spelling of 1917118607831 in words is "one trillion, nine hundred seventeen billion, one hundred eighteen million, six hundred seven thousand, eight hundred thirty-one".