397221009 has 4 divisors (see below), whose sum is σ = 529628016. Its totient is φ = 264814004.

The previous prime is 397221001. The next prime is 397221029. The reversal of 397221009 is 900122793.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 397221009 - 2³ = 397221001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397221001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66203499 + ... + 66203504.

It is an arithmetic number, because the mean of its divisors is an integer number (132407004).

Almost surely, 2^397221009 is an apocalyptic number.

It is an amenable number.

397221009 is a deficient number, since it is larger than the sum of its proper divisors (132407007).

397221009 is a wasteful number, since it uses less digits than its factorization.

397221009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132407006.

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 397221009 is about 19930.4041353907. The cubic root of 397221009 is about 735.0960178137.

The spelling of 397221009 in words is "three hundred ninety-seven million, two hundred twenty-one thousand, nine".