78898294921 has 2 divisors, whose sum is σ = 78898294922. Its totient is φ = 78898294920.

The previous prime is 78898294883. The next prime is 78898294933. The reversal of 78898294921 is 12949289887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56055297600 + 22842997321 = 236760^2 + 151139^2 .

It is a cyclic number.

It is not a de Polignac number, because 78898294921 - 2²⁵ = 78864740489 is a prime.

It is not a weakly prime, because it can be changed into another prime (78898297921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39449147460 + 39449147461.

It is an arithmetic number, because the mean of its divisors is an integer number (39449147461).

Almost surely, 2^78898294921 is an apocalyptic number.

It is an amenable number.

78898294921 is a deficient number, since it is larger than the sum of its proper divisors (1).

78898294921 is an equidigital number, since it uses as much as digits as its factorization.

78898294921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41803776, while the sum is 67.

The spelling of 78898294921 in words is "seventy-eight billion, eight hundred ninety-eight million, two hundred ninety-four thousand, nine hundred twenty-one".