397851091 has 4 divisors (see below), whose sum is σ = 434019384. Its totient is φ = 361682800.

The previous prime is 397851067. The next prime is 397851107. The reversal of 397851091 is 190158793.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190158793 = 11 ⋅17287163.

It is a cyclic number.

It is not a de Polignac number, because 397851091 - 2⁷ = 397850963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (397851001) 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, 18084130 + ... + 18084151.

It is an arithmetic number, because the mean of its divisors is an integer number (108504846).

Almost surely, 2^397851091 is an apocalyptic number.

397851091 is a deficient number, since it is larger than the sum of its proper divisors (36168293).

397851091 is a wasteful number, since it uses less digits than its factorization.

397851091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36168292.

The product of its (nonzero) digits is 68040, while the sum is 43.

The square root of 397851091 is about 19946.2049272537. The cubic root of 397851091 is about 735.4844884438.

The spelling of 397851091 in words is "three hundred ninety-seven million, eight hundred fifty-one thousand, ninety-one".