78767791 has 4 divisors (see below), whose sum is σ = 79289584. Its totient is φ = 78246000.

The previous prime is 78767771. The next prime is 78767797. The reversal of 78767791 is 19776787.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78767791 - 2⁹ = 78767279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78767797) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260670 + ... + 260971.

It is an arithmetic number, because the mean of its divisors is an integer number (19822396).

Almost surely, 2^78767791 is an apocalyptic number.

78767791 is a deficient number, since it is larger than the sum of its proper divisors (521793).

78767791 is a wasteful number, since it uses less digits than its factorization.

78767791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521792.

The product of its digits is 1037232, while the sum is 52.

The square root of 78767791 is about 8875.1220273301. The cubic root of 78767791 is about 428.6632200900.

The spelling of 78767791 in words is "seventy-eight million, seven hundred sixty-seven thousand, seven hundred ninety-one".