671821842 has 32 divisors (see below), whose sum is σ = 1354493952. Its totient is φ = 222140304.

The previous prime is 671821823. The next prime is 671821873. The reversal of 671821842 is 248128176.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 671821842.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 463563 + ... + 465009.

It is an arithmetic number, because the mean of its divisors is an integer number (42327936).

Almost surely, 2^671821842 is an apocalyptic number.

671821842 is an abundant number, since it is smaller than the sum of its proper divisors (682672110).

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

671821842 is a wasteful number, since it uses less digits than its factorization.

671821842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2022.

The product of its digits is 43008, while the sum is 39.

The square root of 671821842 is about 25919.5262688190. The cubic root of 671821842 is about 875.8264157422.

The spelling of 671821842 in words is "six hundred seventy-one million, eight hundred twenty-one thousand, eight hundred forty-two".