821273223985 has 4 divisors (see below), whose sum is σ = 985527868788. Its totient is φ = 657018579184.

The previous prime is 821273223929. The next prime is 821273224003. The reversal of 821273223985 is 589322372128.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 142877196081 + 678396027904 = 377991^2 + 823648^2 .

It is a cyclic number.

It is not a de Polignac number, because 821273223985 - 2¹⁹ = 821272699697 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82127322394 + ... + 82127322403.

It is an arithmetic number, because the mean of its divisors is an integer number (246381967197).

Almost surely, 2^821273223985 is an apocalyptic number.

It is an amenable number.

821273223985 is a deficient number, since it is larger than the sum of its proper divisors (164254644803).

821273223985 is a wasteful number, since it uses less digits than its factorization.

821273223985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164254644802.

The product of its digits is 2903040, while the sum is 52.

The spelling of 821273223985 in words is "eight hundred twenty-one billion, two hundred seventy-three million, two hundred twenty-three thousand, nine hundred eighty-five".