118581921 has 8 divisors (see below), whose sum is σ = 175676960. Its totient is φ = 79054596.

The previous prime is 118581889. The next prime is 118581941. The reversal of 118581921 is 129185811.

It is not a de Polignac number, because 118581921 - 2⁵ = 118581889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118581941) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2195935 + ... + 2195988.

It is an arithmetic number, because the mean of its divisors is an integer number (21959620).

Almost surely, 2^118581921 is an apocalyptic number.

It is an amenable number.

118581921 is a deficient number, since it is larger than the sum of its proper divisors (57095039).

118581921 is an equidigital number, since it uses as much as digits as its factorization.

118581921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4391932 (or 4391926 counting only the distinct ones).

The product of its digits is 5760, while the sum is 36.

The square root of 118581921 is about 10889.5326345992. The cubic root of 118581921 is about 491.2917754812.

The spelling of 118581921 in words is "one hundred eighteen million, five hundred eighty-one thousand, nine hundred twenty-one".