20001161021 has 2 divisors, whose sum is σ = 20001161022. Its totient is φ = 20001161020.

The previous prime is 20001160981. The next prime is 20001161023. The reversal of 20001161021 is 12016110002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12930873796 + 7070287225 = 113714^2 + 84085^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001161021 is a prime.

Together with 20001161023, 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 = 20001160987 and 20001161005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20001161023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000580510 + 10000580511.

It is an arithmetic number, because the mean of its divisors is an integer number (10000580511).

Almost surely, 2^20001161021 is an apocalyptic number.

It is an amenable number.

20001161021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001161021 is an equidigital number, since it uses as much as digits as its factorization.

20001161021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 20001161021 its reverse (12016110002), we get a palindrome (32017271023).

The spelling of 20001161021 in words is "twenty billion, one million, one hundred sixty-one thousand, twenty-one".