78675917 has 2 divisors, whose sum is σ = 78675918. Its totient is φ = 78675916.

The previous prime is 78675899. The next prime is 78675929. The reversal of 78675917 is 71957687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70997476 + 7678441 = 8426^2 + 2771^2 .

It is a cyclic number.

It is not a de Polignac number, because 78675917 - 2¹² = 78671821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78675937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39337958 + 39337959.

It is an arithmetic number, because the mean of its divisors is an integer number (39337959).

Almost surely, 2^78675917 is an apocalyptic number.

It is an amenable number.

78675917 is a deficient number, since it is larger than the sum of its proper divisors (1).

78675917 is an equidigital number, since it uses as much as digits as its factorization.

78675917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 740880, while the sum is 50.

The square root of 78675917 is about 8869.9445883275. The cubic root of 78675917 is about 428.4964923531.

The spelling of 78675917 in words is "seventy-eight million, six hundred seventy-five thousand, nine hundred seventeen".