111611637491 has 4 divisors (see below), whose sum is σ = 114628168272. Its totient is φ = 108595106712.

The previous prime is 111611637407. The next prime is 111611637499. The reversal of 111611637491 is 194736116111.

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-111611637491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111611637499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1508265335 + ... + 1508265408.

It is an arithmetic number, because the mean of its divisors is an integer number (28657042068).

Almost surely, 2^111611637491 is an apocalyptic number.

111611637491 is a deficient number, since it is larger than the sum of its proper divisors (3016530781).

111611637491 is an equidigital number, since it uses as much as digits as its factorization.

111611637491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3016530780.

The product of its digits is 27216, while the sum is 41.

The spelling of 111611637491 in words is "one hundred eleven billion, six hundred eleven million, six hundred thirty-seven thousand, four hundred ninety-one".