117813721 has 2 divisors, whose sum is σ = 117813722. Its totient is φ = 117813720.

The previous prime is 117813719. The next prime is 117813739. The reversal of 117813721 is 127318711.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117072400 + 741321 = 10820^2 + 861^2 .

It is a cyclic number.

It is not a de Polignac number, because 117813721 - 2¹ = 117813719 is a prime.

Together with 117813719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (117813781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58906860 + 58906861.

It is an arithmetic number, because the mean of its divisors is an integer number (58906861).

Almost surely, 2^117813721 is an apocalyptic number.

It is an amenable number.

117813721 is a deficient number, since it is larger than the sum of its proper divisors (1).

117813721 is an equidigital number, since it uses as much as digits as its factorization.

117813721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2352, while the sum is 31.

The square root of 117813721 is about 10854.2029186855. The cubic root of 117813721 is about 490.2285772375.

The spelling of 117813721 in words is "one hundred seventeen million, eight hundred thirteen thousand, seven hundred twenty-one".