118431021 has 4 divisors (see below), whose sum is σ = 157908032. Its totient is φ = 78954012.

The previous prime is 118431017. The next prime is 118431031. The reversal of 118431021 is 120134811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 120134811 = 3 ⋅40044937.

It is not a de Polignac number, because 118431021 - 2² = 118431017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (118431031) 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, 19738501 + ... + 19738506.

It is an arithmetic number, because the mean of its divisors is an integer number (39477008).

Almost surely, 2^118431021 is an apocalyptic number.

It is an amenable number.

118431021 is a deficient number, since it is larger than the sum of its proper divisors (39477011).

118431021 is an equidigital number, since it uses as much as digits as its factorization.

118431021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39477010.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 118431021 is about 10882.6017569329. The cubic root of 118431021 is about 491.0832912045.

Adding to 118431021 its reverse (120134811), we get a palindrome (238565832).

The spelling of 118431021 in words is "one hundred eighteen million, four hundred thirty-one thousand, twenty-one".