397809 has 6 divisors (see below), whose sum is σ = 574626. Its totient is φ = 265200.

The previous prime is 397807. The next prime is 397811. The reversal of 397809 is 908793.

It is an interprime number because it is at equal distance from previous prime (397807) and next prime (397811).

It can be written as a sum of positive squares in only one way, i.e., 278784 + 119025 = 528^2 + 345^2 .

It is not a de Polignac number, because 397809 - 2¹ = 397807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397807) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 22092 + ... + 22109.

It is an arithmetic number, because the mean of its divisors is an integer number (95771).

2³⁹⁷⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

397809 is a deficient number, since it is larger than the sum of its proper divisors (176817).

397809 is a wasteful number, since it uses less digits than its factorization.

397809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44207 (or 44204 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 397809 is about 630.7210159809. The cubic root of 397809 is about 73.5458550457.

The spelling of 397809 in words is "three hundred ninety-seven thousand, eight hundred nine".