397915218 has 12 divisors (see below), whose sum is σ = 862149678. Its totient is φ = 132638400.

The previous prime is 397915213. The next prime is 397915253. The reversal of 397915218 is 812519793.

397915218 is a `hidden beast` number, since 39 + 7 + 91 + 521 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 355963689 + 41951529 = 18867^2 + 6477^2 .

It is not an unprimeable number, because it can be changed into a prime (397915213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11053183 + ... + 11053218.

Almost surely, 2^397915218 is an apocalyptic number.

397915218 is an abundant number, since it is smaller than the sum of its proper divisors (464234460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

397915218 is a wasteful number, since it uses less digits than its factorization.

397915218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22106409 (or 22106406 counting only the distinct ones).

The product of its digits is 136080, while the sum is 45.

The square root of 397915218 is about 19947.8123612591. The cubic root of 397915218 is about 735.5240022896.

The spelling of 397915218 in words is "three hundred ninety-seven million, nine hundred fifteen thousand, two hundred eighteen".