78903621989 has 2 divisors, whose sum is σ = 78903621990. Its totient is φ = 78903621988.

The previous prime is 78903621983. The next prime is 78903621991. The reversal of 78903621989 is 98912630987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39737232964 + 39166389025 = 199342^2 + 197905^2 .

It is a cyclic number.

It is not a de Polignac number, because 78903621989 - 2⁸ = 78903621733 is a prime.

It is a super-2 number, since 2×78903621989² (a number of 23 digits) contains 22 as substring.

Together with 78903621991, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78903621983) 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, 39451810994 + 39451810995.

It is an arithmetic number, because the mean of its divisors is an integer number (39451810995).

Almost surely, 2^78903621989 is an apocalyptic number.

It is an amenable number.

78903621989 is a deficient number, since it is larger than the sum of its proper divisors (1).

78903621989 is an equidigital number, since it uses as much as digits as its factorization.

78903621989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11757312, while the sum is 62.

The spelling of 78903621989 in words is "seventy-eight billion, nine hundred three million, six hundred twenty-one thousand, nine hundred eighty-nine".