78111091 has 8 divisors (see below), whose sum is σ = 80342064. Its totient is φ = 75899040.

The previous prime is 78111083. The next prime is 78111101. The reversal of 78111091 is 19011187.

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

It is a cyclic number.

It is not a de Polignac number, because 78111091 - 2³ = 78111083 is a prime.

It is a super-2 number, since 2×78111091² = 12202685074420562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78111001) 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, 3861 + ... + 13081.

It is an arithmetic number, because the mean of its divisors is an integer number (10042758).

Almost surely, 2^78111091 is an apocalyptic number.

78111091 is a deficient number, since it is larger than the sum of its proper divisors (2230973).

78111091 is a wasteful number, since it uses less digits than its factorization.

78111091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9461.

The product of its (nonzero) digits is 504, while the sum is 28.

The square root of 78111091 is about 8838.0479179511. The cubic root of 78111091 is about 427.4686155043.

The spelling of 78111091 in words is "seventy-eight million, one hundred eleven thousand, ninety-one".