117709981 has 2 divisors, whose sum is σ = 117709982. Its totient is φ = 117709980.

The previous prime is 117709909. The next prime is 117709993. The reversal of 117709981 is 189907711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115369081 + 2340900 = 10741^2 + 1530^2 .

It is a cyclic number.

It is not a de Polignac number, because 117709981 - 2²¹ = 115612829 is a prime.

It is a super-2 number, since 2×117709981² = 27711279254040722, which contains 22 as substring.

It is equal to p_6718597 and since 117709981 and 6718597 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117709901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58854990 + 58854991.

It is an arithmetic number, because the mean of its divisors is an integer number (58854991).

Almost surely, 2^117709981 is an apocalyptic number.

It is an amenable number.

117709981 is a deficient number, since it is larger than the sum of its proper divisors (1).

117709981 is an equidigital number, since it uses as much as digits as its factorization.

117709981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31752, while the sum is 43.

The square root of 117709981 is about 10849.4230722191. The cubic root of 117709981 is about 490.0846459349.

The spelling of 117709981 in words is "one hundred seventeen million, seven hundred nine thousand, nine hundred eighty-one".