78258891 has 8 divisors (see below), whose sum is σ = 109837120. Its totient is φ = 49426632.

The previous prime is 78258863. The next prime is 78258919. The reversal of 78258891 is 19885287.

It is an interprime number because it is at equal distance from previous prime (78258863) and next prime (78258919).

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

It is not a de Polignac number, because 78258891 - 2⁹ = 78258379 is a prime.

It is a super-2 number, since 2×78258891² = 12248908041099762, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 78258891.

It is not an unprimeable number, because it can be changed into a prime (78258821) 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, 686425 + ... + 686538.

It is an arithmetic number, because the mean of its divisors is an integer number (13729640).

Almost surely, 2^78258891 is an apocalyptic number.

78258891 is a deficient number, since it is larger than the sum of its proper divisors (31578229).

78258891 is a wasteful number, since it uses less digits than its factorization.

78258891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1372985.

The product of its digits is 322560, while the sum is 48.

The square root of 78258891 is about 8846.4055412354. The cubic root of 78258891 is about 427.7380610391.

The spelling of 78258891 in words is "seventy-eight million, two hundred fifty-eight thousand, eight hundred ninety-one".