999523 has 4 divisors (see below), whose sum is σ = 1142320. Its totient is φ = 856728.

The previous prime is 999521. The next prime is 999529. The reversal of 999523 is 325999.

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 999523 - 2¹ = 999521 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (999521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71388 + ... + 71401.

It is an arithmetic number, because the mean of its divisors is an integer number (285580).

2⁹⁹⁹⁵²³ is an apocalyptic number.

999523 is a deficient number, since it is larger than the sum of its proper divisors (142797).

999523 is a wasteful number, since it uses less digits than its factorization.

999523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142796.

The product of its digits is 21870, while the sum is 37.

The square root of 999523 is about 999.7614715521. The cubic root of 999523 is about 99.9840974712.

The spelling of 999523 in words is "nine hundred ninety-nine thousand, five hundred twenty-three".