6821891634 has 8 divisors (see below), whose sum is σ = 13643783280. Its totient is φ = 2273963876.

The previous prime is 6821891633. The next prime is 6821891669. The reversal of 6821891634 is 4361981286.

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

6821891634 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (6821891633) 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, 568490964 + ... + 568490975.

It is an arithmetic number, because the mean of its divisors is an integer number (1705472910).

Almost surely, 2^6821891634 is an apocalyptic number.

6821891634 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

6821891634 is a wasteful number, since it uses less digits than its factorization.

6821891634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1136981944.

The product of its digits is 497664, while the sum is 48.

The square root of 6821891634 is about 82594.7433799512. The cubic root of 6821891634 is about 1896.5673602268.

The spelling of 6821891634 in words is "six billion, eight hundred twenty-one million, eight hundred ninety-one thousand, six hundred thirty-four".