78791111 has 4 divisors (see below), whose sum is σ = 90046992. Its totient is φ = 67535232.

The previous prime is 78791099. The next prime is 78791113. The reversal of 78791111 is 11119787.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78791111 is a prime.

It is a super-2 number, since 2×78791111² = 12416078345228642, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78791113) 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, 5627930 + ... + 5627943.

It is an arithmetic number, because the mean of its divisors is an integer number (22511748).

Almost surely, 2^78791111 is an apocalyptic number.

78791111 is a deficient number, since it is larger than the sum of its proper divisors (11255881).

78791111 is a wasteful number, since it uses less digits than its factorization.

78791111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11255880.

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

The square root of 78791111 is about 8876.4357148576. The cubic root of 78791111 is about 428.7055192744.

The spelling of 78791111 in words is "seventy-eight million, seven hundred ninety-one thousand, one hundred eleven".