78993257 has 8 divisors (see below), whose sum is σ = 90737856. Its totient is φ = 67363632.

The previous prime is 78993191. The next prime is 78993259. The reversal of 78993257 is 75239987.

It is a happy number.

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

It is not a de Polignac number, because 78993257 - 2¹² = 78989161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78993259) 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, 27263 + ... + 30020.

It is an arithmetic number, because the mean of its divisors is an integer number (11342232).

Almost surely, 2^78993257 is an apocalyptic number.

It is an amenable number.

78993257 is a deficient number, since it is larger than the sum of its proper divisors (11744599).

78993257 is a wasteful number, since it uses less digits than its factorization.

78993257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57487.

The product of its digits is 952560, while the sum is 50.

The square root of 78993257 is about 8887.8150858352. The cubic root of 78993257 is about 429.0718342806.

The spelling of 78993257 in words is "seventy-eight million, nine hundred ninety-three thousand, two hundred fifty-seven".