78112691 has 4 divisors (see below), whose sum is σ = 78130584. Its totient is φ = 78094800.

The previous prime is 78112649. The next prime is 78112717. The reversal of 78112691 is 19621187.

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 78112691 - 2¹⁰ = 78111667 is a prime.

It is a super-2 number, since 2×78112691² = 12203184990522962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78112091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2396 + ... + 12726.

It is an arithmetic number, because the mean of its divisors is an integer number (19532646).

Almost surely, 2^78112691 is an apocalyptic number.

78112691 is a deficient number, since it is larger than the sum of its proper divisors (17893).

78112691 is a wasteful number, since it uses less digits than its factorization.

78112691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17892.

The product of its digits is 6048, while the sum is 35.

The square root of 78112691 is about 8838.1384352136. The cubic root of 78112691 is about 427.4715341898.

The spelling of 78112691 in words is "seventy-eight million, one hundred twelve thousand, six hundred ninety-one".