117238721 has 18 divisors (see below), whose sum is σ = 128192022. Its totient is φ = 107141760.

The previous prime is 117238717. The next prime is 117238729. The reversal of 117238721 is 127832711.

It can be written as a sum of positive squares in 3 ways, for example, as 5640625 + 111598096 = 2375^2 + 10564^2 .

It is not a de Polignac number, because 117238721 - 2² = 117238717 is a prime.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (117238729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1317245 + ... + 1317333.

It is an arithmetic number, because the mean of its divisors is an integer number (7121779).

Almost surely, 2^117238721 is an apocalyptic number.

It is an amenable number.

117238721 is a deficient number, since it is larger than the sum of its proper divisors (10953301).

117238721 is an frugal number, since it uses more digits than its factorization.

117238721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257 (or 149 counting only the distinct ones).

The product of its digits is 4704, while the sum is 32.

The square root of 117238721 is about 10827.6830854989. The cubic root of 117238721 is about 489.4297419825.

It can be divided in two parts, 1172 and 38721, that added together give a palindrome (39893).

The spelling of 117238721 in words is "one hundred seventeen million, two hundred thirty-eight thousand, seven hundred twenty-one".