397639718 has 16 divisors (see below), whose sum is σ = 689329440. Its totient is φ = 168501696.

The previous prime is 397639691. The next prime is 397639747. The reversal of 397639718 is 817936793.

It is a happy number.

It is a super-2 number, since 2×397639718² = 316234690662239048, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 397639718.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 158321 + ... + 160812.

It is an arithmetic number, because the mean of its divisors is an integer number (43083090).

Almost surely, 2^397639718 is an apocalyptic number.

397639718 is a deficient number, since it is larger than the sum of its proper divisors (291689722).

397639718 is a wasteful number, since it uses less digits than its factorization.

397639718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319231.

The product of its digits is 1714608, while the sum is 53.

The square root of 397639718 is about 19940.9056464344. The cubic root of 397639718 is about 735.3542143237.

The spelling of 397639718 in words is "three hundred ninety-seven million, six hundred thirty-nine thousand, seven hundred eighteen".