972821643821 has 16 divisors (see below), whose sum is σ = 979542701760. Its totient is φ = 966124938240.

The previous prime is 972821643769. The next prime is 972821643823. The reversal of 972821643821 is 128346128279.

It is a cyclic number.

It is not a de Polignac number, because 972821643821 - 2³⁰ = 971747901997 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 (972821643823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 272420966 + ... + 272424536.

It is an arithmetic number, because the mean of its divisors is an integer number (61221418860).

Almost surely, 2^972821643821 is an apocalyptic number.

It is an amenable number.

972821643821 is a deficient number, since it is larger than the sum of its proper divisors (6721057939).

972821643821 is a wasteful number, since it uses less digits than its factorization.

972821643821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6476.

The product of its digits is 2322432, while the sum is 53.

The spelling of 972821643821 in words is "nine hundred seventy-two billion, eight hundred twenty-one million, six hundred forty-three thousand, eight hundred twenty-one".