820920999 has 8 divisors (see below), whose sum is σ = 1095091200. Its totient is φ = 547015736.

The previous prime is 820920979. The next prime is 820921001. The reversal of 820920999 is 999029028.

820920999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 820920999 - 2⁸ = 820920743 is a prime.

It is a super-2 number, since 2×820920999² = 1347822573198316002, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820920979) 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, 58887 + ... + 71480.

It is an arithmetic number, because the mean of its divisors is an integer number (136886400).

Almost surely, 2^820920999 is an apocalyptic number.

820920999 is a deficient number, since it is larger than the sum of its proper divisors (274170201).

820920999 is a wasteful number, since it uses less digits than its factorization.

820920999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132469.

The product of its (nonzero) digits is 209952, while the sum is 48.

The square root of 820920999 is about 28651.7189536684. The cubic root of 820920999 is about 936.3404564050.

The spelling of 820920999 in words is "eight hundred twenty million, nine hundred twenty thousand, nine hundred ninety-nine".