397801999 has 4 divisors (see below), whose sum is σ = 454630864. Its totient is φ = 340973136.

The previous prime is 397801949. The next prime is 397802011. The reversal of 397801999 is 999108793.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 397801999 - 2⁷ = 397801871 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 (397801919) 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 in 3 ways as a sum of consecutive naturals, for example, 28414422 + ... + 28414435.

It is an arithmetic number, because the mean of its divisors is an integer number (113657716).

Almost surely, 2^397801999 is an apocalyptic number.

397801999 is a deficient number, since it is larger than the sum of its proper divisors (56828865).

397801999 is an equidigital number, since it uses as much as digits as its factorization.

397801999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56828864.

The product of its (nonzero) digits is 1102248, while the sum is 55.

The square root of 397801999 is about 19944.9742792514. The cubic root of 397801999 is about 735.4542360114.

The spelling of 397801999 in words is "three hundred ninety-seven million, eight hundred one thousand, nine hundred ninety-nine".