78013057 has 4 divisors (see below), whose sum is σ = 80121556. Its totient is φ = 75904560.

The previous prime is 78013043. The next prime is 78013063. The reversal of 78013057 is 75031087.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 54110736 + 23902321 = 7356^2 + 4889^2 .

It is a cyclic number.

It is not a de Polignac number, because 78013057 - 2²³ = 69624449 is a prime.

It is the 8833-rd Hogben number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78013007) by changing a digit.

It is a nontrivial repunit in base 8832.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1054194 + ... + 1054267.

It is an arithmetic number, because the mean of its divisors is an integer number (20030389).

Almost surely, 2^78013057 is an apocalyptic number.

It is an amenable number.

78013057 is a deficient number, since it is larger than the sum of its proper divisors (2108499).

78013057 is a wasteful number, since it uses less digits than its factorization.

78013057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2108498.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 78013057 is about 8832.5000424568. The cubic root of 78013057 is about 427.2897079099.

The spelling of 78013057 in words is "seventy-eight million, thirteen thousand, fifty-seven".