861117491 has 8 divisors (see below), whose sum is σ = 927803184. Its totient is φ = 794495520.

The previous prime is 861117479. The next prime is 861117529. The reversal of 861117491 is 194711168.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 861117491 - 2¹⁰ = 861116467 is a prime.

It is a super-2 number, since 2×861117491² = 1483046666612270162, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861117421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14276 + ... + 43886.

It is an arithmetic number, because the mean of its divisors is an integer number (115975398).

Almost surely, 2^861117491 is an apocalyptic number.

861117491 is a deficient number, since it is larger than the sum of its proper divisors (66685693).

861117491 is a wasteful number, since it uses less digits than its factorization.

861117491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31861.

The product of its digits is 12096, while the sum is 38.

The square root of 861117491 is about 29344.8034752322. The cubic root of 861117491 is about 951.3802617806.

The spelling of 861117491 in words is "eight hundred sixty-one million, one hundred seventeen thousand, four hundred ninety-one".