999000561 has 16 divisors (see below), whose sum is σ = 1496831616. Its totient is φ = 588039936.

The previous prime is 999000521. The next prime is 999000589. The reversal of 999000561 is 165000999.

It is not a de Polignac number, because 999000561 - 2⁷ = 999000433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (999000521) 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 15 ways as a sum of consecutive naturals, for example, 555960 + ... + 557753.

It is an arithmetic number, because the mean of its divisors is an integer number (93551976).

Almost surely, 2^999000561 is an apocalyptic number.

It is an amenable number.

999000561 is a deficient number, since it is larger than the sum of its proper divisors (497831055).

999000561 is a wasteful number, since it uses less digits than its factorization.

999000561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1113752.

The product of its (nonzero) digits is 21870, while the sum is 39.

The square root of 999000561 is about 31606.9701331842. The cubic root of 999000561 is about 999.6667426185. Note that the first 3 decimals are identical.

The spelling of 999000561 in words is "nine hundred ninety-nine million, five hundred sixty-one", and thus it is an aban number.