118517721 has 24 divisors (see below), whose sum is σ = 184242240. Its totient is φ = 67570272.

The previous prime is 118517717. The next prime is 118517723. The reversal of 118517721 is 127715811.

It is not a de Polignac number, because 118517721 - 2² = 118517717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (118517723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 106315 + ... + 107423.

It is an arithmetic number, because the mean of its divisors is an integer number (7676760).

Almost surely, 2^118517721 is an apocalyptic number.

It is an amenable number.

118517721 is a deficient number, since it is larger than the sum of its proper divisors (65724519).

118517721 is a wasteful number, since it uses less digits than its factorization.

118517721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1853 (or 1846 counting only the distinct ones).

The product of its digits is 3920, while the sum is 33.

The square root of 118517721 is about 10886.5844505979. The cubic root of 118517721 is about 491.2030980350.

The spelling of 118517721 in words is "one hundred eighteen million, five hundred seventeen thousand, seven hundred twenty-one".