78490913 has 2 divisors, whose sum is σ = 78490914. Its totient is φ = 78490912.

The previous prime is 78490903. The next prime is 78490931. The reversal of 78490913 is 31909487.

It is a happy number.

Together with next prime (78490931) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65480464 + 13010449 = 8092^2 + 3607^2 .

It is a cyclic number.

It is not a de Polignac number, because 78490913 - 2¹² = 78486817 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (78490903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39245456 + 39245457.

It is an arithmetic number, because the mean of its divisors is an integer number (39245457).

Almost surely, 2^78490913 is an apocalyptic number.

It is an amenable number.

78490913 is a deficient number, since it is larger than the sum of its proper divisors (1).

78490913 is an equidigital number, since it uses as much as digits as its factorization.

78490913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 78490913 is about 8859.5097494162. The cubic root of 78490913 is about 428.1603633069.

The spelling of 78490913 in words is "seventy-eight million, four hundred ninety thousand, nine hundred thirteen".