78903621917 has 2 divisors, whose sum is σ = 78903621918. Its totient is φ = 78903621916.

The previous prime is 78903621883. The next prime is 78903621947. The reversal of 78903621917 is 71912630987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78854817721 + 48804196 = 280811^2 + 6986^2 .

It is a cyclic number.

It is not a de Polignac number, because 78903621917 - 2¹⁰ = 78903620893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78903621947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39451810958 + 39451810959.

It is an arithmetic number, because the mean of its divisors is an integer number (39451810959).

Almost surely, 2^78903621917 is an apocalyptic number.

It is an amenable number.

78903621917 is a deficient number, since it is larger than the sum of its proper divisors (1).

78903621917 is an equidigital number, since it uses as much as digits as its factorization.

78903621917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The spelling of 78903621917 in words is "seventy-eight billion, nine hundred three million, six hundred twenty-one thousand, nine hundred seventeen".