78613009 has 2 divisors, whose sum is σ = 78613010. Its totient is φ = 78613008.

The previous prime is 78612991. The next prime is 78613019. The reversal of 78613009 is 90031687.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71774784 + 6838225 = 8472^2 + 2615^2 .

It is an emirp because it is prime and its reverse (90031687) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78613009 - 2⁵ = 78612977 is a prime.

It is not a weakly prime, because it can be changed into another prime (78613019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39306504 + 39306505.

It is an arithmetic number, because the mean of its divisors is an integer number (39306505).

Almost surely, 2^78613009 is an apocalyptic number.

It is an amenable number.

78613009 is a deficient number, since it is larger than the sum of its proper divisors (1).

78613009 is an equidigital number, since it uses as much as digits as its factorization.

78613009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 78613009 is about 8866.3977465485. The cubic root of 78613009 is about 428.3822555953.

The spelling of 78613009 in words is "seventy-eight million, six hundred thirteen thousand, nine".