31997198 has 4 divisors (see below), whose sum is σ = 47995800. Its totient is φ = 15998598.

The previous prime is 31997183. The next prime is 31997201. The reversal of 31997198 is 89179913.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89179913 = 8681 ⋅10273.

It is a Curzon number.

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 as a sum of consecutive naturals, namely, 7999298 + ... + 7999301.

It is an arithmetic number, because the mean of its divisors is an integer number (11998950).

Almost surely, 2^31997198 is an apocalyptic number.

31997198 is a deficient number, since it is larger than the sum of its proper divisors (15998602).

31997198 is a wasteful number, since it uses less digits than its factorization.

31997198 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15998601.

The product of its digits is 122472, while the sum is 47.

The square root of 31997198 is about 5656.6065799205. The cubic root of 31997198 is about 317.4709436695.

The spelling of 31997198 in words is "thirty-one million, nine hundred ninety-seven thousand, one hundred ninety-eight".