397156789 has 4 divisors (see below), whose sum is σ = 403888320. Its totient is φ = 390425260.

The previous prime is 397156759. The next prime is 397156819. The reversal of 397156789 is 987651793.

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 an interprime number because it is at equal distance from previous prime (397156759) and next prime (397156819).

It is a cyclic number.

It is not a de Polignac number, because 397156789 - 2¹⁹ = 396632501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397156759) 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, 3365677 + ... + 3365794.

It is an arithmetic number, because the mean of its divisors is an integer number (100972080).

Almost surely, 2^397156789 is an apocalyptic number.

It is an amenable number.

397156789 is a deficient number, since it is larger than the sum of its proper divisors (6731531).

397156789 is an equidigital number, since it uses as much as digits as its factorization.

397156789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6731530.

The product of its digits is 2857680, while the sum is 55.

The square root of 397156789 is about 19928.7929639504. The cubic root of 397156789 is about 735.0564005650.

The spelling of 397156789 in words is "three hundred ninety-seven million, one hundred fifty-six thousand, seven hundred eighty-nine".