999564 has 24 divisors (see below), whose sum is σ = 2408448. Its totient is φ = 322320.

The previous prime is 999563. The next prime is 999599. The reversal of 999564 is 465999.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (999563) 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, 972 + ... + 1715.

It is an arithmetic number, because the mean of its divisors is an integer number (100352).

2⁹⁹⁹⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

999564 is an abundant number, since it is smaller than the sum of its proper divisors (1408884).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

999564 is a wasteful number, since it uses less digits than its factorization.

999564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2725 (or 2723 counting only the distinct ones).

The product of its digits is 87480, while the sum is 42.

The square root of 999564 is about 999.7819762328. The cubic root of 999564 is about 99.9854645540.

The spelling of 999564 in words is "nine hundred ninety-nine thousand, five hundred sixty-four".