397567909 has 4 divisors (see below), whose sum is σ = 400236300. Its totient is φ = 394899520.

The previous prime is 397567897. The next prime is 397567943. The reversal of 397567909 is 909765793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 909765793 = 47 ⋅19356719.

It can be written as a sum of positive squares in 2 ways, for example, as 187607809 + 209960100 = 13697^2 + 14490^2 .

It is a cyclic number.

It is not a de Polignac number, because 397567909 - 2²⁵ = 364013477 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 397567909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397567969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1333972 + ... + 1334269.

It is an arithmetic number, because the mean of its divisors is an integer number (100059075).

Almost surely, 2^397567909 is an apocalyptic number.

It is an amenable number.

397567909 is a deficient number, since it is larger than the sum of its proper divisors (2668391).

397567909 is a wasteful number, since it uses less digits than its factorization.

397567909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2668390.

The product of its (nonzero) digits is 3214890, while the sum is 55.

The square root of 397567909 is about 19939.1050200354. The cubic root of 397567909 is about 735.3099462528.

The spelling of 397567909 in words is "three hundred ninety-seven million, five hundred sixty-seven thousand, nine hundred nine".