78081173 has 2 divisors, whose sum is σ = 78081174. Its totient is φ = 78081172.

The previous prime is 78081167. The next prime is 78081233. The reversal of 78081173 is 37118087.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76073284 + 2007889 = 8722^2 + 1417^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78081173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78081473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39040586 + 39040587.

It is an arithmetic number, because the mean of its divisors is an integer number (39040587).

Almost surely, 2^78081173 is an apocalyptic number.

It is an amenable number.

78081173 is a deficient number, since it is larger than the sum of its proper divisors (1).

78081173 is an equidigital number, since it uses as much as digits as its factorization.

78081173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9408, while the sum is 35.

The square root of 78081173 is about 8836.3551875193. The cubic root of 78081173 is about 427.4140323927.

The spelling of 78081173 in words is "seventy-eight million, eighty-one thousand, one hundred seventy-three".