397388691 has 48 divisors (see below), whose sum is σ = 667989504. Its totient is φ = 222976512.

The previous prime is 397388689. The next prime is 397388699. The reversal of 397388691 is 196883793.

It is not a de Polignac number, because 397388691 - 2¹ = 397388689 is a prime.

It is not an unprimeable number, because it can be changed into a prime (397388699) 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 47 ways as a sum of consecutive naturals, for example, 1125571 + ... + 1125923.

It is an arithmetic number, because the mean of its divisors is an integer number (13916448).

Almost surely, 2^397388691 is an apocalyptic number.

397388691 is a deficient number, since it is larger than the sum of its proper divisors (270600813).

397388691 is a wasteful number, since it uses less digits than its factorization.

397388691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 637 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 54.

The square root of 397388691 is about 19934.6103799397. The cubic root of 397388691 is about 735.1994405324.

The spelling of 397388691 in words is "three hundred ninety-seven million, three hundred eighty-eight thousand, six hundred ninety-one".