79257139 has 4 divisors (see below), whose sum is σ = 85353856. Its totient is φ = 73160424.

The previous prime is 79257137. The next prime is 79257193. The reversal of 79257139 is 93175297.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93175297 = 19 ⋅4903963.

It is a cyclic number.

It is not a de Polignac number, because 79257139 - 2¹ = 79257137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 79257095 and 79257104.

It is not an unprimeable number, because it can be changed into a prime (79257131) 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, 3048339 + ... + 3048364.

It is an arithmetic number, because the mean of its divisors is an integer number (21338464).

Almost surely, 2^79257139 is an apocalyptic number.

79257139 is a deficient number, since it is larger than the sum of its proper divisors (6096717).

79257139 is a wasteful number, since it uses less digits than its factorization.

79257139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6096716.

The product of its digits is 119070, while the sum is 43.

The square root of 79257139 is about 8902.6478645401. The cubic root of 79257139 is about 429.5490838326.

The spelling of 79257139 in words is "seventy-nine million, two hundred fifty-seven thousand, one hundred thirty-nine".