78865256887 has 4 divisors (see below), whose sum is σ = 78865903600. Its totient is φ = 78864610176.

The previous prime is 78865256881. The next prime is 78865256909.

78865256887 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 78865256887 - 2³¹ = 76717773239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78865256881) 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, 78762 + ... + 404887.

It is an arithmetic number, because the mean of its divisors is an integer number (19716475900).

Almost surely, 2^78865256887 is an apocalyptic number.

78865256887 is a deficient number, since it is larger than the sum of its proper divisors (646713).

78865256887 is a wasteful number, since it uses less digits than its factorization.

78865256887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646712.

The product of its digits is 361267200, while the sum is 70.

The spelling of 78865256887 in words is "seventy-eight billion, eight hundred sixty-five million, two hundred fifty-six thousand, eight hundred eighty-seven".