999642 has 16 divisors (see below), whose sum is σ = 2284992. Its totient is φ = 285600.

The previous prime is 999631. The next prime is 999653. The reversal of 999642 is 246999.

999642 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (999631) and next prime (999653).

It is a super-3 number, since 3×999642³ = 2996779153338351864, which contains 333 as substring.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 999642.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11859 + ... + 11942.

It is an arithmetic number, because the mean of its divisors is an integer number (142812).

2⁹⁹⁹⁶⁴² is an apocalyptic number.

999642 is an abundant number, since it is smaller than the sum of its proper divisors (1285350).

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

999642 is a wasteful number, since it uses less digits than its factorization.

999642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23813.

The product of its digits is 34992, while the sum is 39.

The square root of 999642 is about 999.8209839766. The cubic root of 999642 is about 99.9880652423.

The spelling of 999642 in words is "nine hundred ninety-nine thousand, six hundred forty-two".