117917978 has 4 divisors (see below), whose sum is σ = 176876970. Its totient is φ = 58958988.

The previous prime is 117917957. The next prime is 117917981. The reversal of 117917978 is 879719711.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 879719711 = 13 ⋅67670747.

It can be written as a sum of positive squares in only one way, i.e., 113784889 + 4133089 = 10667^2 + 2033^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 29479493 + ... + 29479496.

Almost surely, 2^117917978 is an apocalyptic number.

117917978 is a deficient number, since it is larger than the sum of its proper divisors (58958992).

117917978 is an equidigital number, since it uses as much as digits as its factorization.

117917978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58958991.

The product of its digits is 222264, while the sum is 50.

The square root of 117917978 is about 10859.0044663404. The cubic root of 117917978 is about 490.3731407387.

The spelling of 117917978 in words is "one hundred seventeen million, nine hundred seventeen thousand, nine hundred seventy-eight".