78176845121 has 2 divisors, whose sum is σ = 78176845122. Its totient is φ = 78176845120.

The previous prime is 78176845093. The next prime is 78176845231. The reversal of 78176845121 is 12154867187.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55469670400 + 22707174721 = 235520^2 + 150689^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78176845121 is a prime.

It is a super-3 number, since 3×78176845121³ (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 78176845121.

It is not a weakly prime, because it can be changed into another prime (78176845321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39088422560 + 39088422561.

It is an arithmetic number, because the mean of its divisors is an integer number (39088422561).

Almost surely, 2^78176845121 is an apocalyptic number.

It is an amenable number.

78176845121 is a deficient number, since it is larger than the sum of its proper divisors (1).

78176845121 is an equidigital number, since it uses as much as digits as its factorization.

78176845121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 752640, while the sum is 50.

The spelling of 78176845121 in words is "seventy-eight billion, one hundred seventy-six million, eight hundred forty-five thousand, one hundred twenty-one".