78117911 has 8 divisors (see below), whose sum is σ = 82311600. Its totient is φ = 73932480.

The previous prime is 78117899. The next prime is 78117929. The reversal of 78117911 is 11971187.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78117911 is a prime.

It is a super-2 number, since 2×78117911² = 12204816038007842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78117931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31505 + ... + 33893.

It is an arithmetic number, because the mean of its divisors is an integer number (10288950).

Almost surely, 2^78117911 is an apocalyptic number.

78117911 is a deficient number, since it is larger than the sum of its proper divisors (4193689).

78117911 is a wasteful number, since it uses less digits than its factorization.

78117911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4129.

The product of its digits is 3528, while the sum is 35.

The square root of 78117911 is about 8838.4337413368. The cubic root of 78117911 is about 427.4810561239.

The spelling of 78117911 in words is "seventy-eight million, one hundred seventeen thousand, nine hundred eleven".