78851057 has 4 divisors (see below), whose sum is σ = 78898596. Its totient is φ = 78803520.

The previous prime is 78851041. The next prime is 78851099. The reversal of 78851057 is 75015887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75015887 = 2287 ⋅32801.

It can be written as a sum of positive squares in 2 ways, for example, as 64705936 + 14145121 = 8044^2 + 3761^2 .

It is a cyclic number.

It is not a de Polignac number, because 78851057 - 2⁴ = 78851041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78851257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21188 + ... + 24629.

It is an arithmetic number, because the mean of its divisors is an integer number (19724649).

Almost surely, 2^78851057 is an apocalyptic number.

It is an amenable number.

78851057 is a deficient number, since it is larger than the sum of its proper divisors (47539).

78851057 is a wasteful number, since it uses less digits than its factorization.

78851057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47538.

The product of its (nonzero) digits is 78400, while the sum is 41.

The square root of 78851057 is about 8879.8117660230. The cubic root of 78851057 is about 428.8142145573.

The spelling of 78851057 in words is "seventy-eight million, eight hundred fifty-one thousand, fifty-seven".