397790689 has 2 divisors, whose sum is σ = 397790690. Its totient is φ = 397790688.

The previous prime is 397790671. The next prime is 397790693. The reversal of 397790689 is 986097793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 375700689 + 22090000 = 19383^2 + 4700^2 .

It is an emirp because it is prime and its reverse (986097793) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397790689 is a prime.

It is not a weakly prime, because it can be changed into another prime (397790629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198895344 + 198895345.

It is an arithmetic number, because the mean of its divisors is an integer number (198895345).

Almost surely, 2^397790689 is an apocalyptic number.

It is an amenable number.

397790689 is a deficient number, since it is larger than the sum of its proper divisors (1).

397790689 is an equidigital number, since it uses as much as digits as its factorization.

397790689 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5143824, while the sum is 58.

The square root of 397790689 is about 19944.6907471638. The cubic root of 397790689 is about 735.4472659893.

The spelling of 397790689 in words is "three hundred ninety-seven million, seven hundred ninety thousand, six hundred eighty-nine".