820988 has 24 divisors (see below), whose sum is σ = 1663200. Its totient is φ = 347328.

The previous prime is 820969. The next prime is 820991. The reversal of 820988 is 889028.

It is a super-2 number, since 2×820988² = 1348042592288, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820988.

It is an unprimeable number.

820988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2918 + ... + 3186.

It is an arithmetic number, because the mean of its divisors is an integer number (69300).

2⁸²⁰⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

820988 is an abundant number, since it is smaller than the sum of its proper divisors (842212).

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

820988 is a wasteful number, since it uses less digits than its factorization.

820988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389 (or 387 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 820988 is about 906.0838813267. The cubic root of 820988 is about 93.6365929437.

The spelling of 820988 in words is "eight hundred twenty thousand, nine hundred eighty-eight".