78642857215 has 16 divisors (see below), whose sum is σ = 101640889728. Its totient is φ = 58068942336.

The previous prime is 78642857213. The next prime is 78642857261. The reversal of 78642857215 is 51275824687.

It is a cyclic number.

It is not a de Polignac number, because 78642857215 - 2¹ = 78642857213 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 (78642857213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 663994 + ... + 773416.

It is an arithmetic number, because the mean of its divisors is an integer number (6352555608).

Almost surely, 2^78642857215 is an apocalyptic number.

78642857215 is a deficient number, since it is larger than the sum of its proper divisors (22998032513).

78642857215 is a wasteful number, since it uses less digits than its factorization.

78642857215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120498.

The product of its digits is 7526400, while the sum is 55.

The spelling of 78642857215 in words is "seventy-eight billion, six hundred forty-two million, eight hundred fifty-seven thousand, two hundred fifteen".