118721905 has 4 divisors (see below), whose sum is σ = 142466292. Its totient is φ = 94977520.

The previous prime is 118721903. The next prime is 118721927. The reversal of 118721905 is 509127811.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55487601 + 63234304 = 7449^2 + 7952^2 .

It is not a de Polignac number, because 118721905 - 2¹ = 118721903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118721903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11872186 + ... + 11872195.

It is an arithmetic number, because the mean of its divisors is an integer number (35616573).

Almost surely, 2^118721905 is an apocalyptic number.

It is an amenable number.

118721905 is a deficient number, since it is larger than the sum of its proper divisors (23744387).

118721905 is an equidigital number, since it uses as much as digits as its factorization.

118721905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23744386.

The product of its (nonzero) digits is 5040, while the sum is 34.

The square root of 118721905 is about 10895.9581955879. The cubic root of 118721905 is about 491.4850200704.

The spelling of 118721905 in words is "one hundred eighteen million, seven hundred twenty-one thousand, nine hundred five".