397988317 has 4 divisors (see below), whose sum is σ = 408744796. Its totient is φ = 387231840.

The previous prime is 397988303. The next prime is 397988329. The reversal of 397988317 is 713889793.

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

It can be written as a sum of positive squares in 2 ways, for example, as 343509156 + 54479161 = 18534^2 + 7381^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-397988317 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 (397988347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5378184 + ... + 5378257.

It is an arithmetic number, because the mean of its divisors is an integer number (102186199).

Almost surely, 2^397988317 is an apocalyptic number.

397988317 is a gapful number since it is divisible by the number (37) formed by its first and last digit.

It is an amenable number.

397988317 is a deficient number, since it is larger than the sum of its proper divisors (10756479).

397988317 is a wasteful number, since it uses less digits than its factorization.

397988317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10756478.

The product of its digits is 2286144, while the sum is 55.

The square root of 397988317 is about 19949.6445331740. The cubic root of 397988317 is about 735.5690393349.

The spelling of 397988317 in words is "three hundred ninety-seven million, nine hundred eighty-eight thousand, three hundred seventeen".