872821643821 has 8 divisors (see below), whose sum is σ = 874552474400. Its totient is φ = 871092448560.

The previous prime is 872821643801. The next prime is 872821643833. The reversal of 872821643821 is 128346128278.

872821643821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 872821643821 - 2³⁵ = 838461905453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (872821643801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 662470 + ... + 1478008.

It is an arithmetic number, because the mean of its divisors is an integer number (109319059300).

Almost surely, 2^872821643821 is an apocalyptic number.

It is an amenable number.

872821643821 is a deficient number, since it is larger than the sum of its proper divisors (1730830579).

872821643821 is a wasteful number, since it uses less digits than its factorization.

872821643821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817659.

The product of its digits is 2064384, while the sum is 52.

The spelling of 872821643821 in words is "eight hundred seventy-two billion, eight hundred twenty-one million, six hundred forty-three thousand, eight hundred twenty-one".