20011121221001 has 2 divisors, whose sum is σ = 20011121221002. Its totient is φ = 20011121221000.

The previous prime is 20011121220949. The next prime is 20011121221057. The reversal of 20011121221001 is 10012212111002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12930604687225 + 7080516533776 = 3595915^2 + 2660924^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20011121221001 is a prime.

It is not a weakly prime, because it can be changed into another prime (20011121221061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10005560610500 + 10005560610501.

It is an arithmetic number, because the mean of its divisors is an integer number (10005560610501).

Almost surely, 2^{20011121221001} is an apocalyptic number.

It is an amenable number.

20011121221001 is a deficient number, since it is larger than the sum of its proper divisors (1).

20011121221001 is an equidigital number, since it uses as much as digits as its factorization.

20011121221001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 20011121221001 its reverse (10012212111002), we get a palindrome (30023333332003).

The spelling of 20011121221001 in words is "twenty trillion, eleven billion, one hundred twenty-one million, two hundred twenty-one thousand, one".