78107107861 has 2 divisors, whose sum is σ = 78107107862. Its totient is φ = 78107107860.

The previous prime is 78107107849. The next prime is 78107107877. The reversal of 78107107861 is 16870170187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67987955025 + 10119152836 = 260745^2 + 100594^2 .

It is a cyclic number.

It is not a de Polignac number, because 78107107861 - 2⁵ = 78107107829 is a prime.

It is a super-2 number, since 2×78107107861² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78107107831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39053553930 + 39053553931.

It is an arithmetic number, because the mean of its divisors is an integer number (39053553931).

Almost surely, 2^78107107861 is an apocalyptic number.

It is an amenable number.

78107107861 is a deficient number, since it is larger than the sum of its proper divisors (1).

78107107861 is an equidigital number, since it uses as much as digits as its factorization.

78107107861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 131712, while the sum is 46.

The spelling of 78107107861 in words is "seventy-eight billion, one hundred seven million, one hundred seven thousand, eight hundred sixty-one".