2100101021 has 2 divisors, whose sum is σ = 2100101022. Its totient is φ = 2100101020.

The previous prime is 2100101009. The next prime is 2100101039. The reversal of 2100101021 is 1201010012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1657629796 + 442471225 = 40714^2 + 21035^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100101021 - 2⁶ = 2100100957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100101071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050050510 + 1050050511.

It is an arithmetic number, because the mean of its divisors is an integer number (1050050511).

Almost surely, 2^2100101021 is an apocalyptic number.

It is an amenable number.

2100101021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100101021 is an equidigital number, since it uses as much as digits as its factorization.

2100101021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 2100101021 is about 45826.8591657774. The cubic root of 2100101021 is about 1280.5996988468.

Adding to 2100101021 its reverse (1201010012), we get a palindrome (3301111033).

The spelling of 2100101021 in words is "two billion, one hundred million, one hundred one thousand, twenty-one".