2100121081 has 2 divisors, whose sum is σ = 2100121082. Its totient is φ = 2100121080.

The previous prime is 2100121057. The next prime is 2100121103. The reversal of 2100121081 is 1801210012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1102572025 + 997549056 = 33205^2 + 31584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2100121081 is a prime.

It is a super-2 number, since 2×2100121081² = 8821017109721217122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2100121021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050060540 + 1050060541.

It is an arithmetic number, because the mean of its divisors is an integer number (1050060541).

Almost surely, 2^2100121081 is an apocalyptic number.

It is an amenable number.

2100121081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2100121081 is an equidigital number, since it uses as much as digits as its factorization.

2100121081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

The square root of 2100121081 is about 45827.0780325344. The cubic root of 2100121081 is about 1280.6037762297.

Adding to 2100121081 its reverse (1801210012), we get a palindrome (3901331093).

The spelling of 2100121081 in words is "two billion, one hundred million, one hundred twenty-one thousand, eighty-one".