820645194 has 16 divisors (see below), whose sum is σ = 1641574368. Its totient is φ = 273501072.

The previous prime is 820645151. The next prime is 820645229. The reversal of 820645194 is 491546028.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53409 + ... + 67035.

It is an arithmetic number, because the mean of its divisors is an integer number (102598398).

Almost surely, 2^820645194 is an apocalyptic number.

820645194 is an abundant number, since it is smaller than the sum of its proper divisors (820929174).

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

820645194 is a wasteful number, since it uses less digits than its factorization.

820645194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23669.

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 820645194 is about 28646.9054873297. The cubic root of 820645194 is about 936.2355838263.

The spelling of 820645194 in words is "eight hundred twenty million, six hundred forty-five thousand, one hundred ninety-four".