78628857 has 8 divisors (see below), whose sum is σ = 107395680. Its totient is φ = 51140640.

The previous prime is 78628853. The next prime is 78628867. The reversal of 78628857 is 75882687.

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

It is not a de Polignac number, because 78628857 - 2² = 78628853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (78628853) 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, 319507 + ... + 319752.

It is an arithmetic number, because the mean of its divisors is an integer number (13424460).

Almost surely, 2^78628857 is an apocalyptic number.

It is an amenable number.

78628857 is a deficient number, since it is larger than the sum of its proper divisors (28766823).

78628857 is a wasteful number, since it uses less digits than its factorization.

78628857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 639303.

The product of its digits is 1505280, while the sum is 51.

The square root of 78628857 is about 8867.2914128273. The cubic root of 78628857 is about 428.4110402537.

The spelling of 78628857 in words is "seventy-eight million, six hundred twenty-eight thousand, eight hundred fifty-seven".