2001102121021 has 2 divisors, whose sum is σ = 2001102121022. Its totient is φ = 2001102121020.

The previous prime is 2001102121009. The next prime is 2001102121049. The reversal of 2001102121021 is 1201212011002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1732092888100 + 269009232921 = 1316090^2 + 518661^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001102121021 - 2⁹ = 2001102120509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001102120992 and 2001102121010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001102121061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000551060510 + 1000551060511.

It is an arithmetic number, because the mean of its divisors is an integer number (1000551060511).

Almost surely, 2^{2001102121021} is an apocalyptic number.

It is an amenable number.

2001102121021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001102121021 is an equidigital number, since it uses as much as digits as its factorization.

2001102121021 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 13.

Adding to 2001102121021 its reverse (1201212011002), we get a palindrome (3202314132023).

The spelling of 2001102121021 in words is "two trillion, one billion, one hundred two million, one hundred twenty-one thousand, twenty-one".