118151681 has 4 divisors (see below), whose sum is σ = 120381012. Its totient is φ = 115922352.

The previous prime is 118151641. The next prime is 118151687. The reversal of 118151681 is 186151811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186151811 = 23 ⋅8093557.

It can be written as a sum of positive squares in 2 ways, for example, as 60528400 + 57623281 = 7780^2 + 7591^2 .

It is a cyclic number.

It is not a de Polignac number, because 118151681 - 2⁶ = 118151617 is a prime.

It is a super-2 number, since 2×118151681² = 27919639446251522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118151687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1114586 + ... + 1114691.

It is an arithmetic number, because the mean of its divisors is an integer number (30095253).

Almost surely, 2^118151681 is an apocalyptic number.

It is an amenable number.

118151681 is a deficient number, since it is larger than the sum of its proper divisors (2229331).

118151681 is an equidigital number, since it uses as much as digits as its factorization.

118151681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2229330.

The product of its digits is 1920, while the sum is 32.

The square root of 118151681 is about 10869.7599329516. The cubic root of 118151681 is about 490.6968856818.

The spelling of 118151681 in words is "one hundred eighteen million, one hundred fifty-one thousand, six hundred eighty-one".