2102123281 has 2 divisors, whose sum is σ = 2102123282. Its totient is φ = 2102123280.

The previous prime is 2102123279. The next prime is 2102123323. The reversal of 2102123281 is 1823212012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1479171600 + 622951681 = 38460^2 + 24959^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102123281 - 2¹ = 2102123279 is a prime.

It is a super-2 number, since 2×2102123281² = 8837844577044409922, which contains 22 as substring.

Together with 2102123279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2102127281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1051061640 + 1051061641.

It is an arithmetic number, because the mean of its divisors is an integer number (1051061641).

Almost surely, 2^2102123281 is an apocalyptic number.

It is an amenable number.

2102123281 is a deficient number, since it is larger than the sum of its proper divisors (1).

2102123281 is an equidigital number, since it uses as much as digits as its factorization.

2102123281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 2102123281 is about 45848.9179915950. The cubic root of 2102123281 is about 1281.0106115801.

Adding to 2102123281 its reverse (1823212012), we get a palindrome (3925335293).

The spelling of 2102123281 in words is "two billion, one hundred two million, one hundred twenty-three thousand, two hundred eighty-one".