820891043 has 8 divisors (see below), whose sum is σ = 945549312. Its totient is φ = 698079816.

The previous prime is 820891039. The next prime is 820891051. The reversal of 820891043 is 340198028.

It is a happy number.

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

It is not a de Polignac number, because 820891043 - 2² = 820891039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 820890994 and 820891012.

It is not an unprimeable number, because it can be changed into a prime (820891063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 460805 + ... + 462582.

It is an arithmetic number, because the mean of its divisors is an integer number (118193664).

Almost surely, 2^820891043 is an apocalyptic number.

820891043 is a deficient number, since it is larger than the sum of its proper divisors (124658269).

820891043 is a wasteful number, since it uses less digits than its factorization.

820891043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923521.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 820891043 is about 28651.1961879430. The cubic root of 820891043 is about 936.3290670200.

The spelling of 820891043 in words is "eight hundred twenty million, eight hundred ninety-one thousand, forty-three".