78898630021 has 2 divisors, whose sum is σ = 78898630022. Its totient is φ = 78898630020.

The previous prime is 78898630001. The next prime is 78898630039. The reversal of 78898630021 is 12003689887.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78490185921 + 408444100 = 280161^2 + 20210^2 .

It is a cyclic number.

It is not a de Polignac number, because 78898630021 - 2⁷ = 78898629893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78898630001) 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, 39449315010 + 39449315011.

It is an arithmetic number, because the mean of its divisors is an integer number (39449315011).

Almost surely, 2^78898630021 is an apocalyptic number.

It is an amenable number.

78898630021 is a deficient number, since it is larger than the sum of its proper divisors (1).

78898630021 is an equidigital number, since it uses as much as digits as its factorization.

78898630021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1161216, while the sum is 52.

The spelling of 78898630021 in words is "seventy-eight billion, eight hundred ninety-eight million, six hundred thirty thousand, twenty-one".