397478991 has 32 divisors (see below), whose sum is σ = 655298560. Its totient is φ = 208687104.

The previous prime is 397478981. The next prime is 397479011. The reversal of 397478991 is 199874793.

It is not a de Polignac number, because 397478991 - 2¹¹ = 397476943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397478981) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 57615 + ... + 64143.

It is an arithmetic number, because the mean of its divisors is an integer number (20478080).

Almost surely, 2^397478991 is an apocalyptic number.

397478991 is a deficient number, since it is larger than the sum of its proper divisors (257819569).

397478991 is a wasteful number, since it uses less digits than its factorization.

397478991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6775.

The product of its digits is 3429216, while the sum is 57.

The square root of 397478991 is about 19936.8751563529. The cubic root of 397478991 is about 735.2551236147.

The spelling of 397478991 in words is "three hundred ninety-seven million, four hundred seventy-eight thousand, nine hundred ninety-one".