20001201209831 has 2 divisors, whose sum is σ = 20001201209832. Its totient is φ = 20001201209830.

The previous prime is 20001201209711. The next prime is 20001201209833. The reversal of 20001201209831 is 13890210210002.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001201209831 is a prime.

It is a super-2 number, since 2×20001201209831² (a number of 27 digits) contains 22 as substring.

Together with 20001201209833, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001201209794 and 20001201209803.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001201209833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000600604915 + 10000600604916.

It is an arithmetic number, because the mean of its divisors is an integer number (10000600604916).

Almost surely, 2^{20001201209831} is an apocalyptic number.

20001201209831 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001201209831 is an equidigital number, since it uses as much as digits as its factorization.

20001201209831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

Adding to 20001201209831 its reverse (13890210210002), we get a palindrome (33891411419833).

The spelling of 20001201209831 in words is "twenty trillion, one billion, two hundred one million, two hundred nine thousand, eight hundred thirty-one".