78385091 has 4 divisors (see below), whose sum is σ = 78501552. Its totient is φ = 78268632.

The previous prime is 78385033. The next prime is 78385093. The reversal of 78385091 is 19058387.

It is a happy number.

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 78385091 - 2¹⁰ = 78384067 is a prime.

It is a super-2 number, since 2×78385091² = 12288444982156562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78385093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57215 + ... + 58568.

It is an arithmetic number, because the mean of its divisors is an integer number (19625388).

Almost surely, 2^78385091 is an apocalyptic number.

78385091 is a deficient number, since it is larger than the sum of its proper divisors (116461).

78385091 is a wasteful number, since it uses less digits than its factorization.

78385091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116460.

The product of its (nonzero) digits is 60480, while the sum is 41.

The square root of 78385091 is about 8853.5355084847. The cubic root of 78385091 is about 427.9678605004.

The spelling of 78385091 in words is "seventy-eight million, three hundred eighty-five thousand, ninety-one".