999990331 has 4 divisors (see below), whose sum is σ = 1000420200. Its totient is φ = 999560464.

The previous prime is 999990319. The next prime is 999990347. The reversal of 999990331 is 133099999.

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 999990331 - 2¹⁹ = 999466043 is a prime.

It is a super-3 number, since 3×999990331³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999990301) 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, 211426 + ... + 216103.

It is an arithmetic number, because the mean of its divisors is an integer number (250105050).

Almost surely, 2^999990331 is an apocalyptic number.

999990331 is a deficient number, since it is larger than the sum of its proper divisors (429869).

999990331 is a wasteful number, since it uses less digits than its factorization.

999990331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429868.

The product of its (nonzero) digits is 531441, while the sum is 52.

The square root of 999990331 is about 31622.6237210008. The cubic root of 999990331 is about 999.9967769896.

The spelling of 999990331 in words is "nine hundred ninety-nine million, nine hundred ninety thousand, three hundred thirty-one".