8390473439021 has 2 divisors, whose sum is σ = 8390473439022. Its totient is φ = 8390473439020.

The previous prime is 8390473438987. The next prime is 8390473439041. The reversal of 8390473439021 is 1209343740938.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7643483149225 + 746990289796 = 2764685^2 + 864286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8390473439021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8390473439041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4195236719510 + 4195236719511.

It is an arithmetic number, because the mean of its divisors is an integer number (4195236719511).

Almost surely, 2^{8390473439021} is an apocalyptic number.

It is an amenable number.

8390473439021 is a deficient number, since it is larger than the sum of its proper divisors (1).

8390473439021 is an equidigital number, since it uses as much as digits as its factorization.

8390473439021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3919104, while the sum is 53.

The spelling of 8390473439021 in words is "eight trillion, three hundred ninety billion, four hundred seventy-three million, four hundred thirty-nine thousand, twenty-one".