397517849 has 2 divisors, whose sum is σ = 397517850. Its totient is φ = 397517848.

The previous prime is 397517839. The next prime is 397517893. The reversal of 397517849 is 948715793.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 361000000 + 36517849 = 19000^2 + 6043^2 .

It is an emirp because it is prime and its reverse (948715793) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 397517849 - 2⁴ = 397517833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 397517849.

It is not a weakly prime, because it can be changed into another prime (397517839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198758924 + 198758925.

It is an arithmetic number, because the mean of its divisors is an integer number (198758925).

Almost surely, 2^397517849 is an apocalyptic number.

It is an amenable number.

397517849 is a deficient number, since it is larger than the sum of its proper divisors (1).

397517849 is an equidigital number, since it uses as much as digits as its factorization.

397517849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1905120, while the sum is 53.

The square root of 397517849 is about 19937.8496583759. The cubic root of 397517849 is about 735.2790826274.

The spelling of 397517849 in words is "three hundred ninety-seven million, five hundred seventeen thousand, eight hundred forty-nine".