231997 has 4 divisors (see below), whose sum is σ = 234396. Its totient is φ = 229600.

The previous prime is 231967. The next prime is 232003. The reversal of 231997 is 799132.

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 177241 + 54756 = 421^2 + 234^2 .

It is a cyclic number.

It is not a de Polignac number, because 231997 - 2¹¹ = 229949 is a prime.

It is a Duffinian number.

231997 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231947) 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, 1048 + ... + 1249.

It is an arithmetic number, because the mean of its divisors is an integer number (58599).

2²³¹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

231997 is a deficient number, since it is larger than the sum of its proper divisors (2399).

231997 is a wasteful number, since it uses less digits than its factorization.

231997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2398.

The product of its digits is 3402, while the sum is 31.

The square root of 231997 is about 481.6606689361. The cubic root of 231997 is about 61.4460716577.

The spelling of 231997 in words is "two hundred thirty-one thousand, nine hundred ninety-seven".