231001999 has 4 divisors (see below), whose sum is σ = 231200440. Its totient is φ = 230803560.

The previous prime is 231001963. The next prime is 231002027. The reversal of 231001999 is 999100132.

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

It is a cyclic number.

It is not a de Polignac number, because 231001999 - 2¹⁵ = 230969231 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231001919) 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 3 ways as a sum of consecutive naturals, for example, 97464 + ... + 99805.

It is an arithmetic number, because the mean of its divisors is an integer number (57800110).

Almost surely, 2^231001999 is an apocalyptic number.

231001999 is a deficient number, since it is larger than the sum of its proper divisors (198441).

231001999 is a wasteful number, since it uses less digits than its factorization.

231001999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198440.

The product of its (nonzero) digits is 4374, while the sum is 34.

The square root of 231001999 is about 15198.7499157003. The cubic root of 231001999 is about 613.5810138672.

The spelling of 231001999 in words is "two hundred thirty-one million, one thousand, nine hundred ninety-nine".