990780 has 72 divisors (see below), whose sum is σ = 3236688. Its totient is φ = 225792.

The previous prime is 990767. The next prime is 990797. The reversal of 990780 is 87099.

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

990780 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 23 ways as a sum of consecutive naturals, for example, 2772 + ... + 3108.

It is an arithmetic number, because the mean of its divisors is an integer number (44954).

2⁹⁹⁰⁷⁸⁰ 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 990780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1618344).

990780 is an abundant number, since it is smaller than the sum of its proper divisors (2245908).

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

990780 is a wasteful number, since it uses less digits than its factorization.

990780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 363 (or 354 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 990780 is about 995.3793246798. The cubic root of 990780 is about 99.6917172608.

It can be divided in two parts, 990 and 780, that added together give a triangular number (1770 = T₅₉).

The spelling of 990780 in words is "nine hundred ninety thousand, seven hundred eighty".