999405 has 32 divisors (see below), whose sum is σ = 1941120. Its totient is φ = 483840.

The previous prime is 999389. The next prime is 999431. The reversal of 999405 is 504999.

It is not a de Polignac number, because 999405 - 2⁴ = 999389 is a prime.

999405 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 999405.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 999405.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1149 + ... + 1821.

It is an arithmetic number, because the mean of its divisors is an integer number (60660).

2⁹⁹⁹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

999405 is a deficient number, since it is larger than the sum of its proper divisors (941715).

999405 is a wasteful number, since it uses less digits than its factorization.

999405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698 (or 692 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The square root of 999405 is about 999.7024557337. The cubic root of 999405 is about 99.9801627318.

The spelling of 999405 in words is "nine hundred ninety-nine thousand, four hundred five".