117840781 has 2 divisors, whose sum is σ = 117840782. Its totient is φ = 117840780.

The previous prime is 117840773. The next prime is 117840803. The reversal of 117840781 is 187048711.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117397225 + 443556 = 10835^2 + 666^2 .

It is a cyclic number.

It is not a de Polignac number, because 117840781 - 2³ = 117840773 is a prime.

It is a super-2 number, since 2×117840781² = 27772899333379922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 117840781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (117840721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 58920390 + 58920391.

It is an arithmetic number, because the mean of its divisors is an integer number (58920391).

Almost surely, 2^117840781 is an apocalyptic number.

It is an amenable number.

117840781 is a deficient number, since it is larger than the sum of its proper divisors (1).

117840781 is an equidigital number, since it uses as much as digits as its factorization.

117840781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12544, while the sum is 37.

The square root of 117840781 is about 10855.4493688654. The cubic root of 117840781 is about 490.2661070195.

The spelling of 117840781 in words is "one hundred seventeen million, eight hundred forty thousand, seven hundred eighty-one".