821123721201 has 16 divisors (see below), whose sum is σ = 1255853262848. Its totient is φ = 467482136400.

The previous prime is 821123721193. The next prime is 821123721227. The reversal of 821123721201 is 102127321128.

It is not a de Polignac number, because 821123721201 - 2³ = 821123721193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821123721401) 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, 72136615 + ... + 72147996.

It is an arithmetic number, because the mean of its divisors is an integer number (78490828928).

Almost surely, 2^821123721201 is an apocalyptic number.

It is an amenable number.

821123721201 is a deficient number, since it is larger than the sum of its proper divisors (434729541647).

821123721201 is a wasteful number, since it uses less digits than its factorization.

821123721201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144284892.

The product of its (nonzero) digits is 2688, while the sum is 30.

The spelling of 821123721201 in words is "eight hundred twenty-one billion, one hundred twenty-three million, seven hundred twenty-one thousand, two hundred one".