2123132009861 has 2 divisors, whose sum is σ = 2123132009862. Its totient is φ = 2123132009860.

The previous prime is 2123132009857. The next prime is 2123132010031. The reversal of 2123132009861 is 1689002313212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1206469379236 + 916662630625 = 1098394^2 + 957425^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123132009861 - 2² = 2123132009857 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2123132009851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1061566004930 + 1061566004931.

It is an arithmetic number, because the mean of its divisors is an integer number (1061566004931).

Almost surely, 2^{2123132009861} is an apocalyptic number.

It is an amenable number.

2123132009861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123132009861 is an equidigital number, since it uses as much as digits as its factorization.

2123132009861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 38.

The spelling of 2123132009861 in words is "two trillion, one hundred twenty-three billion, one hundred thirty-two million, nine thousand, eight hundred sixty-one".