20011120021 has 2 divisors, whose sum is σ = 20011120022. Its totient is φ = 20011120020.

The previous prime is 20011119983. The next prime is 20011120039. The reversal of 20011120021 is 12002111002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17183539396 + 2827580625 = 131086^2 + 53175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011120021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20011120061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005560010 + 10005560011.

It is an arithmetic number, because the mean of its divisors is an integer number (10005560011).

Almost surely, 2^20011120021 is an apocalyptic number.

It is an amenable number.

20011120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011120021 is an equidigital number, since it uses as much as digits as its factorization.

20011120021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 20011120021 its reverse (12002111002), we get a palindrome (32013231023).

The spelling of 20011120021 in words is "twenty billion, eleven million, one hundred twenty thousand, twenty-one".