78972558361 has 2 divisors, whose sum is σ = 78972558362. Its totient is φ = 78972558360.

The previous prime is 78972558317. The next prime is 78972558389. The reversal of 78972558361 is 16385527987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62210336400 + 16762221961 = 249420^2 + 129469^2 .

It is a cyclic number.

It is not a de Polignac number, because 78972558361 - 2²⁵ = 78939003929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78972558361.

It is not a weakly prime, because it can be changed into another prime (78972558061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39486279180 + 39486279181.

It is an arithmetic number, because the mean of its divisors is an integer number (39486279181).

Almost surely, 2^78972558361 is an apocalyptic number.

It is an amenable number.

78972558361 is a deficient number, since it is larger than the sum of its proper divisors (1).

78972558361 is an equidigital number, since it uses as much as digits as its factorization.

78972558361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25401600, while the sum is 61.

The spelling of 78972558361 in words is "seventy-eight billion, nine hundred seventy-two million, five hundred fifty-eight thousand, three hundred sixty-one".