999231 has 8 divisors (see below), whose sum is σ = 1338624. Its totient is φ = 663000.

The previous prime is 999221. The next prime is 999233. The reversal of 999231 is 132999.

999231 is nontrivially palindromic in base 16.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 999231 - 2⁵ = 999199 is a prime.

It is a super-2 number, since 2×999231² = 1996925182722, which contains 22 as substring.

999231 is an undulating number in base 16.

999231 is a lucky number.

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 999192 and 999201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90 + ... + 1416.

It is an arithmetic number, because the mean of its divisors is an integer number (167328).

2⁹⁹⁹²³¹ is an apocalyptic number.

999231 is a deficient number, since it is larger than the sum of its proper divisors (339393).

999231 is a wasteful number, since it uses less digits than its factorization.

999231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1581.

The product of its digits is 4374, while the sum is 33.

The square root of 999231 is about 999.6154260514. The cubic root of 999231 is about 99.9743600932.

The spelling of 999231 in words is "nine hundred ninety-nine thousand, two hundred thirty-one".