789910021 has 2 divisors, whose sum is σ = 789910022. Its totient is φ = 789910020.

The previous prime is 789910001. The next prime is 789910063. The reversal of 789910021 is 120019987.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 728460100 + 61449921 = 26990^2 + 7839^2 .

It is an emirp because it is prime and its reverse (120019987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 789910021 - 2⁷ = 789909893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (789910001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 394955010 + 394955011.

It is an arithmetic number, because the mean of its divisors is an integer number (394955011).

Almost surely, 2^789910021 is an apocalyptic number.

It is an amenable number.

789910021 is a deficient number, since it is larger than the sum of its proper divisors (1).

789910021 is an equidigital number, since it uses as much as digits as its factorization.

789910021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 789910021 is about 28105.3379449527. The cubic root of 789910021 is about 924.3984483249.

The spelling of 789910021 in words is "seven hundred eighty-nine million, nine hundred ten thousand, twenty-one".