78990111 has 12 divisors (see below), whose sum is σ = 114503688. Its totient is φ = 52472304.

The previous prime is 78990103. The next prime is 78990133. The reversal of 78990111 is 11109987.

It is not a de Polignac number, because 78990111 - 2³ = 78990103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78990101) 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, 12960 + ... + 18053.

It is an arithmetic number, because the mean of its divisors is an integer number (9541974).

Almost surely, 2^78990111 is an apocalyptic number.

78990111 is a deficient number, since it is larger than the sum of its proper divisors (35513577).

78990111 is a wasteful number, since it uses less digits than its factorization.

78990111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31302 (or 31299 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 36.

The square root of 78990111 is about 8887.6381001929. The cubic root of 78990111 is about 429.0661381070.

The spelling of 78990111 in words is "seventy-eight million, nine hundred ninety thousand, one hundred eleven".