2100101921 has 2 divisors, whose sum is σ = 2100101922. Its totient is φ = 2100101920.

The previous prime is 2100101909. The next prime is 2100101957. The reversal of 2100101921 is 1291010012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1492972321 + 607129600 = 38639^2 + 24640^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100101921 - 2¹⁰ = 2100100897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2100101921.

It is not a weakly prime, because it can be changed into another prime (2100101021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050050960 + 1050050961.

It is an arithmetic number, because the mean of its divisors is an integer number (1050050961).

Almost surely, 2^2100101921 is an apocalyptic number.

It is an amenable number.

2100101921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100101921 is an equidigital number, since it uses as much as digits as its factorization.

2100101921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 17.

The square root of 2100101921 is about 45826.8689853453. The cubic root of 2100101921 is about 1280.5998817808.

Adding to 2100101921 its reverse (1291010012), we get a palindrome (3391111933).

The spelling of 2100101921 in words is "two billion, one hundred million, one hundred one thousand, nine hundred twenty-one".