821880 has 64 divisors (see below), whose sum is σ = 2743200. Its totient is φ = 218880.

The previous prime is 821879. The next prime is 821897. The reversal of 821880 is 88128.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 700 + ... + 1460.

2⁸²¹⁸⁸⁰ 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 821880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1371600).

821880 is an abundant number, since it is smaller than the sum of its proper divisors (1921320).

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

821880 is a wasteful number, since it uses less digits than its factorization.

821880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 781 (or 771 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 821880 is about 906.5759758564. The cubic root of 821880 is about 93.6704925905.

The spelling of 821880 in words is "eight hundred twenty-one thousand, eight hundred eighty".