397478009 has 2 divisors, whose sum is σ = 397478010. Its totient is φ = 397478008.

The previous prime is 397477937. The next prime is 397478021. The reversal of 397478009 is 900874793.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 224160784 + 173317225 = 14972^2 + 13165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397478009 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (397478069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198739004 + 198739005.

It is an arithmetic number, because the mean of its divisors is an integer number (198739005).

Almost surely, 2^397478009 is an apocalyptic number.

It is an amenable number.

397478009 is a deficient number, since it is larger than the sum of its proper divisors (1).

397478009 is an equidigital number, since it uses as much as digits as its factorization.

397478009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 381024, while the sum is 47.

The square root of 397478009 is about 19936.8505286066. The cubic root of 397478009 is about 735.2545181142.

The spelling of 397478009 in words is "three hundred ninety-seven million, four hundred seventy-eight thousand, nine".