20001085821 has 24 divisors (see below), whose sum is σ = 30559553856. Its totient is φ = 12579589440.

The previous prime is 20001085763. The next prime is 20001085843. The reversal of 20001085821 is 12858010002.

It is not a de Polignac number, because 20001085821 - 2⁶ = 20001085757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001085861) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 646695 + ... + 676916.

It is an arithmetic number, because the mean of its divisors is an integer number (1273314744).

Almost surely, 2^20001085821 is an apocalyptic number.

It is an amenable number.

20001085821 is a deficient number, since it is larger than the sum of its proper divisors (10558468035).

20001085821 is a wasteful number, since it uses less digits than its factorization.

20001085821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1323713 (or 1323710 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

Adding to 20001085821 its reverse (12858010002), we get a palindrome (32859095823).

The spelling of 20001085821 in words is "twenty billion, one million, eighty-five thousand, eight hundred twenty-one".