990864 has 60 divisors (see below), whose sum is σ = 3172416. Its totient is φ = 282816.

The previous prime is 990851. The next prime is 990881. The reversal of 990864 is 468099.

990864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×990864² = 1963622932992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is an unprimeable number.

990864 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 517 + ... + 1499.

2⁹⁹⁰⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 990864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1586208).

990864 is an abundant number, since it is smaller than the sum of its proper divisors (2181552).

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

990864 is a wasteful number, since it uses less digits than its factorization.

990864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1004 (or 995 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 990864 is about 995.4215187547. The cubic root of 990864 is about 99.6945345252.

The spelling of 990864 in words is "nine hundred ninety thousand, eight hundred sixty-four".