845787989 has 2 divisors, whose sum is σ = 845787990. Its totient is φ = 845787988.

The previous prime is 845787979. The next prime is 845787991. The reversal of 845787989 is 989787548.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 513928900 + 331859089 = 22670^2 + 18217^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-845787989 is a prime.

Together with 845787991, 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 (845787959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422893994 + 422893995.

It is an arithmetic number, because the mean of its divisors is an integer number (422893995).

Almost surely, 2^845787989 is an apocalyptic number.

It is an amenable number.

845787989 is a deficient number, since it is larger than the sum of its proper divisors (1).

845787989 is an equidigital number, since it uses as much as digits as its factorization.

845787989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40642560, while the sum is 65.

The square root of 845787989 is about 29082.4343719710. The cubic root of 845787989 is about 945.7009772493.

The spelling of 845787989 in words is "eight hundred forty-five million, seven hundred eighty-seven thousand, nine hundred eighty-nine".