820932891 has 4 divisors (see below), whose sum is σ = 1094577192. Its totient is φ = 547288592.

The previous prime is 820932881. The next prime is 820932911. The reversal of 820932891 is 198239028.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-820932891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (820932811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136822146 + ... + 136822151.

It is an arithmetic number, because the mean of its divisors is an integer number (273644298).

Almost surely, 2^820932891 is an apocalyptic number.

820932891 is a deficient number, since it is larger than the sum of its proper divisors (273644301).

820932891 is a wasteful number, since it uses less digits than its factorization.

820932891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273644300.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 820932891 is about 28651.9264797326. The cubic root of 820932891 is about 936.3449777117.

The spelling of 820932891 in words is "eight hundred twenty million, nine hundred thirty-two thousand, eight hundred ninety-one".