116211991 has 16 divisors (see below), whose sum is σ = 134611200. Its totient is φ = 98273088.

The previous prime is 116211973. The next prime is 116212007. The reversal of 116211991 is 199112611.

It is a cyclic number.

It is not a de Polignac number, because 116211991 - 2⁷ = 116211863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (116211691) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203955 + ... + 204523.

It is an arithmetic number, because the mean of its divisors is an integer number (8413200).

Almost surely, 2^116211991 is an apocalyptic number.

116211991 is a deficient number, since it is larger than the sum of its proper divisors (18399209).

116211991 is a wasteful number, since it uses less digits than its factorization.

116211991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 918.

The product of its digits is 972, while the sum is 31.

The square root of 116211991 is about 10780.1665571549. The cubic root of 116211991 is about 487.9968072330.

The spelling of 116211991 in words is "one hundred sixteen million, two hundred eleven thousand, nine hundred ninety-one".