2100211120981 has 2 divisors, whose sum is σ = 2100211120982. Its totient is φ = 2100211120980.

The previous prime is 2100211120951. The next prime is 2100211120991. The reversal of 2100211120981 is 1890211120012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2000623540356 + 99587580625 = 1414434^2 + 315575^2 .

It is a cyclic number.

It is not a de Polignac number, because 2100211120981 - 2¹⁷ = 2100210989909 is a prime.

It is a super-2 number, since 2×2100211120981² (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 (2100211120951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050105560490 + 1050105560491.

It is an arithmetic number, because the mean of its divisors is an integer number (1050105560491).

Almost surely, 2^{2100211120981} is an apocalyptic number.

It is an amenable number.

2100211120981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100211120981 is an equidigital number, since it uses as much as digits as its factorization.

2100211120981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 28.

Adding to 2100211120981 its reverse (1890211120012), we get a palindrome (3990422240993).

The spelling of 2100211120981 in words is "two trillion, one hundred billion, two hundred eleven million, one hundred twenty thousand, nine hundred eighty-one".