990231 has 16 divisors (see below), whose sum is σ = 1481088. Its totient is φ = 583200.

The previous prime is 990211. The next prime is 990239. The reversal of 990231 is 132099.

It is a happy number.

It is not a de Polignac number, because 990231 - 2⁹ = 989719 is a prime.

It is a super-2 number, since 2×990231² = 1961114866722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 816 + ... + 1626.

It is an arithmetic number, because the mean of its divisors is an integer number (92568).

2⁹⁹⁰²³¹ is an apocalyptic number.

990231 is a deficient number, since it is larger than the sum of its proper divisors (490857).

990231 is a wasteful number, since it uses less digits than its factorization.

990231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862.

The product of its (nonzero) digits is 486, while the sum is 24.

The square root of 990231 is about 995.1035122036. The cubic root of 990231 is about 99.6733005034.

It can be divided in two parts, 990 and 231, that added together give a palindrome (1221).

The spelling of 990231 in words is "nine hundred ninety thousand, two hundred thirty-one".