2100212099981 has 2 divisors, whose sum is σ = 2100212099982. Its totient is φ = 2100212099980.

The previous prime is 2100212099971. The next prime is 2100212100017. The reversal of 2100212099981 is 1899902120012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2078957375881 + 21254724100 = 1441859^2 + 145790^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100212099981 - 2³⁰ = 2099138358157 is a prime.

It is a super-2 number, since 2×2100212099981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2100212099941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050106049990 + 1050106049991.

It is an arithmetic number, because the mean of its divisors is an integer number (1050106049991).

Almost surely, 2^{2100212099981} is an apocalyptic number.

It is an amenable number.

2100212099981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100212099981 is an equidigital number, since it uses as much as digits as its factorization.

2100212099981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 44.

The spelling of 2100212099981 in words is "two trillion, one hundred billion, two hundred twelve million, ninety-nine thousand, nine hundred eighty-one".