397918 has 4 divisors (see below), whose sum is σ = 596880. Its totient is φ = 198958.

The previous prime is 397907. The next prime is 397921. The reversal of 397918 is 819793.

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

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99478 + ... + 99481.

It is an arithmetic number, because the mean of its divisors is an integer number (149220).

2³⁹⁷⁹¹⁸ is an apocalyptic number.

397918 is a deficient number, since it is larger than the sum of its proper divisors (198962).

397918 is a wasteful number, since it uses less digits than its factorization.

397918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198961.

The product of its digits is 13608, while the sum is 37.

The square root of 397918 is about 630.8074191067. The cubic root of 397918 is about 73.5525716409.

Subtracting 397918 from its reverse (819793), we obtain a cube (421875 = 75³).

The spelling of 397918 in words is "three hundred ninety-seven thousand, nine hundred eighteen".