78804128257 has 8 divisors (see below), whose sum is σ = 81527244840. Its totient is φ = 76081393920.

The previous prime is 78804128251. The next prime is 78804128267. The reversal of 78804128257 is 75282140887.

It can be written as a sum of positive squares in 4 ways, for example, as 25365021696 + 53439106561 = 159264^2 + 231169^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 78804128257 - 2¹¹ = 78804126209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78804128251) 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, 360907 + ... + 536527.

It is an arithmetic number, because the mean of its divisors is an integer number (10190905605).

Almost surely, 2^78804128257 is an apocalyptic number.

It is an amenable number.

78804128257 is a deficient number, since it is larger than the sum of its proper divisors (2723116583).

78804128257 is a wasteful number, since it uses less digits than its factorization.

78804128257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191123.

The product of its (nonzero) digits is 2007040, while the sum is 52.

The spelling of 78804128257 in words is "seventy-eight billion, eight hundred four million, one hundred twenty-eight thousand, two hundred fifty-seven".