117778561 has 12 divisors (see below), whose sum is σ = 125330688. Its totient is φ = 110471504.

The previous prime is 117778559. The next prime is 117778589. The reversal of 117778561 is 165877711.

It is not a de Polignac number, because 117778561 - 2¹ = 117778559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (117778361) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 63696 + ... + 65518.

It is an arithmetic number, because the mean of its divisors is an integer number (10444224).

Almost surely, 2^117778561 is an apocalyptic number.

It is an amenable number.

117778561 is a deficient number, since it is larger than the sum of its proper divisors (7552127).

117778561 is an equidigital number, since it uses as much as digits as its factorization.

117778561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1952 (or 1899 counting only the distinct ones).

The product of its digits is 82320, while the sum is 43.

The square root of 117778561 is about 10852.5831487255. The cubic root of 117778561 is about 490.1798048999.

The spelling of 117778561 in words is "one hundred seventeen million, seven hundred seventy-eight thousand, five hundred sixty-one".