820981161 has 48 divisors (see below), whose sum is σ = 1592223360. Its totient is φ = 393672960.

The previous prime is 820981151. The next prime is 820981163. The reversal of 820981161 is 161189028.

It is not a de Polignac number, because 820981161 - 2⁷ = 820981033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (820981163) 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 47 ways as a sum of consecutive naturals, for example, 36556 + ... + 54573.

It is an arithmetic number, because the mean of its divisors is an integer number (33171320).

Almost surely, 2^820981161 is an apocalyptic number.

It is an amenable number.

820981161 is a deficient number, since it is larger than the sum of its proper divisors (771242199).

820981161 is a wasteful number, since it uses less digits than its factorization.

820981161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91166 (or 91163 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 36.

The square root of 820981161 is about 28652.7688190862. The cubic root of 820981161 is about 936.3633293889.

The spelling of 820981161 in words is "eight hundred twenty million, nine hundred eighty-one thousand, one hundred sixty-one".