117645581 has 2 divisors, whose sum is σ = 117645582. Its totient is φ = 117645580.

The previous prime is 117645557. The next prime is 117645601. The reversal of 117645581 is 185546711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59428681 + 58216900 = 7709^2 + 7630^2 .

It is a cyclic number.

It is not a de Polignac number, because 117645581 - 2¹⁰ = 117644557 is a prime.

It is a super-2 number, since 2×117645581² = 27680965457655122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117645551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58822790 + 58822791.

It is an arithmetic number, because the mean of its divisors is an integer number (58822791).

Almost surely, 2^117645581 is an apocalyptic number.

It is an amenable number.

117645581 is a deficient number, since it is larger than the sum of its proper divisors (1).

117645581 is an equidigital number, since it uses as much as digits as its factorization.

117645581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33600, while the sum is 38.

The square root of 117645581 is about 10846.4547664202. The cubic root of 117645581 is about 489.9952533207.

The spelling of 117645581 in words is "one hundred seventeen million, six hundred forty-five thousand, five hundred eighty-one".