78642857213 has 2 divisors, whose sum is σ = 78642857214. Its totient is φ = 78642857212.

The previous prime is 78642857177. The next prime is 78642857261. The reversal of 78642857213 is 31275824687.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78634254724 + 8602489 = 280418^2 + 2933^2 .

It is a cyclic number.

It is not a de Polignac number, because 78642857213 - 2¹⁰ = 78642856189 is a prime.

It is a super-2 number, since 2×78642857213² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78642850213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39321428606 + 39321428607.

It is an arithmetic number, because the mean of its divisors is an integer number (39321428607).

Almost surely, 2^78642857213 is an apocalyptic number.

It is an amenable number.

78642857213 is a deficient number, since it is larger than the sum of its proper divisors (1).

78642857213 is an equidigital number, since it uses as much as digits as its factorization.

78642857213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4515840, while the sum is 53.

The spelling of 78642857213 in words is "seventy-eight billion, six hundred forty-two million, eight hundred fifty-seven thousand, two hundred thirteen".