78975257 has 4 divisors (see below), whose sum is σ = 79019556. Its totient is φ = 78930960.

The previous prime is 78975223. The next prime is 78975263. The reversal of 78975257 is 75257987.

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 40398736 + 38576521 = 6356^2 + 6211^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78975257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78975277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19358 + ... + 23079.

It is an arithmetic number, because the mean of its divisors is an integer number (19754889).

Almost surely, 2^78975257 is an apocalyptic number.

It is an amenable number.

78975257 is a deficient number, since it is larger than the sum of its proper divisors (44299).

78975257 is a wasteful number, since it uses less digits than its factorization.

78975257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44298.

The product of its digits is 1234800, while the sum is 50.

The square root of 78975257 is about 8886.8024058150. The cubic root of 78975257 is about 429.0392412888.

The spelling of 78975257 in words is "seventy-eight million, nine hundred seventy-five thousand, two hundred fifty-seven".