118709721 has 24 divisors (see below), whose sum is σ = 187698056. Its totient is φ = 71850240.

The previous prime is 118709699. The next prime is 118709849. The reversal of 118709721 is 127907811.

It can be written as a sum of positive squares in 4 ways, for example, as 10653696 + 108056025 = 3264^2 + 10395^2 .

It is a de Polignac number, because none of the positive numbers 2^k-118709721 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (118709021) 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, 1180 + ... + 15453.

Almost surely, 2^118709721 is an apocalyptic number.

It is an amenable number.

118709721 is a deficient number, since it is larger than the sum of its proper divisors (68988335).

118709721 is a wasteful number, since it uses less digits than its factorization.

118709721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16713 (or 16710 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 36.

The square root of 118709721 is about 10895.3990748389. The cubic root of 118709721 is about 491.4682063848.

The spelling of 118709721 in words is "one hundred eighteen million, seven hundred nine thousand, seven hundred twenty-one".