78425261 has 2 divisors, whose sum is σ = 78425262. Its totient is φ = 78425260.

The previous prime is 78425231. The next prime is 78425317. The reversal of 78425261 is 16252487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68376361 + 10048900 = 8269^2 + 3170^2 .

It is an emirp because it is prime and its reverse (16252487) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78425261 is a prime.

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 (78425231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39212630 + 39212631.

It is an arithmetic number, because the mean of its divisors is an integer number (39212631).

Almost surely, 2^78425261 is an apocalyptic number.

It is an amenable number.

78425261 is a deficient number, since it is larger than the sum of its proper divisors (1).

78425261 is an equidigital number, since it uses as much as digits as its factorization.

78425261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 35.

The square root of 78425261 is about 8855.8038031564. The cubic root of 78425261 is about 428.0409548983.

The spelling of 78425261 in words is "seventy-eight million, four hundred twenty-five thousand, two hundred sixty-one".