999964 has 24 divisors (see below), whose sum is σ = 2032128. Its totient is φ = 421680.

The previous prime is 999961. The next prime is 999979. The reversal of 999964 is 469999.

It is a happy number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999961) 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, 1737 + ... + 2239.

It is an arithmetic number, because the mean of its divisors is an integer number (84672).

999964 is a Friedman number, since it can be written as (9+9/9)^6-9*4, using all its digits and the basic arithmetic operations.

2⁹⁹⁹⁹⁶⁴ is an apocalyptic number.

It is an amenable number.

999964 is an abundant number, since it is smaller than the sum of its proper divisors (1032164).

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

999964 is a wasteful number, since it uses less digits than its factorization.

999964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 585 (or 583 counting only the distinct ones).

The product of its digits is 157464, while the sum is 46.

The square root of 999964 is about 999.9819998380. The cubic root of 999964 is about 99.9987999856.

It can be divided in two parts, 99996 and 4, that added together give a 5-th power (100000 = 10⁵).

The spelling of 999964 in words is "nine hundred ninety-nine thousand, nine hundred sixty-four".