117639581 has 2 divisors, whose sum is σ = 117639582. Its totient is φ = 117639580.

The previous prime is 117639551. The next prime is 117639589. The reversal of 117639581 is 185936711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64480900 + 53158681 = 8030^2 + 7291^2 .

It is a cyclic number.

It is not a de Polignac number, because 117639581 - 2⁶ = 117639517 is a prime.

It is a super-2 number, since 2×117639581² = 27678142035711122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117639589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58819790 + 58819791.

It is an arithmetic number, because the mean of its divisors is an integer number (58819791).

Almost surely, 2^117639581 is an apocalyptic number.

It is an amenable number.

117639581 is a deficient number, since it is larger than the sum of its proper divisors (1).

117639581 is an equidigital number, since it uses as much as digits as its factorization.

117639581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 41.

The square root of 117639581 is about 10846.1781748227. The cubic root of 117639581 is about 489.9869231551.

The spelling of 117639581 in words is "one hundred seventeen million, six hundred thirty-nine thousand, five hundred eighty-one".