20001131021 has 2 divisors, whose sum is σ = 20001131022. Its totient is φ = 20001131020.

The previous prime is 20001130997. The next prime is 20001131053. The reversal of 20001131021 is 12013110002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17092686121 + 2908444900 = 130739^2 + 53930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001131021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20001130993 and 20001131011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001161021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000565510 + 10000565511.

It is an arithmetic number, because the mean of its divisors is an integer number (10000565511).

Almost surely, 2^20001131021 is an apocalyptic number.

It is an amenable number.

20001131021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001131021 is an equidigital number, since it uses as much as digits as its factorization.

20001131021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12, while the sum is 11.

Adding to 20001131021 its reverse (12013110002), we get a palindrome (32014241023).

The spelling of 20001131021 in words is "twenty billion, one million, one hundred thirty-one thousand, twenty-one".