78370091 has 2 divisors, whose sum is σ = 78370092. Its totient is φ = 78370090.

The previous prime is 78370087. The next prime is 78370109. The reversal of 78370091 is 19007387.

Together with next prime (78370109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78370091 - 2² = 78370087 is a prime.

It is a super-2 number, since 2×78370091² = 12283742326696562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78370001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39185045 + 39185046.

It is an arithmetic number, because the mean of its divisors is an integer number (39185046).

Almost surely, 2^78370091 is an apocalyptic number.

78370091 is a deficient number, since it is larger than the sum of its proper divisors (1).

78370091 is an equidigital number, since it uses as much as digits as its factorization.

78370091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10584, while the sum is 35.

The square root of 78370091 is about 8852.6883487447. The cubic root of 78370091 is about 427.9405596989.

The spelling of 78370091 in words is "seventy-eight million, three hundred seventy thousand, ninety-one".