2100099961 has 2 divisors, whose sum is σ = 2100099962. Its totient is φ = 2100099960.

The previous prime is 2100099917. The next prime is 2100099977. The reversal of 2100099961 is 1699900012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1393603561 + 706496400 = 37331^2 + 26580^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100099961 - 2¹⁷ = 2099968889 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2100099961.

It is not a weakly prime, because it can be changed into another prime (2100099901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050049980 + 1050049981.

It is an arithmetic number, because the mean of its divisors is an integer number (1050049981).

Almost surely, 2^2100099961 is an apocalyptic number.

It is an amenable number.

2100099961 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100099961 is an equidigital number, since it uses as much as digits as its factorization.

2100099961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8748, while the sum is 37.

The square root of 2100099961 is about 45826.8476005060. The cubic root of 2100099961 is about 1280.5994833911.

Adding to 2100099961 its reverse (1699900012), we get a palindrome (3799999973).

The spelling of 2100099961 in words is "two billion, one hundred million, ninety-nine thousand, nine hundred sixty-one".