2100121021021 has 2 divisors, whose sum is σ = 2100121021022. Its totient is φ = 2100121021020.

The previous prime is 2100121020983. The next prime is 2100121021039. The reversal of 2100121021021 is 1201201210012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2067875636121 + 32245384900 = 1438011^2 + 179570^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100121021021 - 2³⁹ = 1550365207133 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2100121020992 and 2100121021010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100121621021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050060510510 + 1050060510511.

It is an arithmetic number, because the mean of its divisors is an integer number (1050060510511).

Almost surely, 2^{2100121021021} is an apocalyptic number.

It is an amenable number.

2100121021021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100121021021 is an equidigital number, since it uses as much as digits as its factorization.

2100121021021 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 2100121021021 its reverse (1201201210012), we get a palindrome (3301322231033).

The spelling of 2100121021021 in words is "two trillion, one hundred billion, one hundred twenty-one million, twenty-one thousand, twenty-one".