397855807 has 2 divisors, whose sum is σ = 397855808. Its totient is φ = 397855806.

The previous prime is 397855793. The next prime is 397855831. The reversal of 397855807 is 708558793.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 397855807 - 2¹⁵ = 397823039 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (397855837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 198927903 + 198927904.

It is an arithmetic number, because the mean of its divisors is an integer number (198927904).

Almost surely, 2^397855807 is an apocalyptic number.

397855807 is a deficient number, since it is larger than the sum of its proper divisors (1).

397855807 is an equidigital number, since it uses as much as digits as its factorization.

397855807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2116800, while the sum is 52.

The square root of 397855807 is about 19946.3231448806. The cubic root of 397855807 is about 735.4873944986.

The spelling of 397855807 in words is "three hundred ninety-seven million, eight hundred fifty-five thousand, eight hundred seven".