2102749681 has 2 divisors, whose sum is σ = 2102749682. Its totient is φ = 2102749680.

The previous prime is 2102749679. The next prime is 2102749711. The reversal of 2102749681 is 1869472012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1384509681 + 718240000 = 37209^2 + 26800^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102749681 - 2¹ = 2102749679 is a prime.

It is a super-2 number, since 2×2102749681² = 8843112441891203522, which contains 22 as substring.

Together with 2102749679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2102749651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1051374840 + 1051374841.

It is an arithmetic number, because the mean of its divisors is an integer number (1051374841).

Almost surely, 2^2102749681 is an apocalyptic number.

It is an amenable number.

2102749681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2102749681 is an equidigital number, since it uses as much as digits as its factorization.

2102749681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 2102749681 is about 45855.7486145412. The cubic root of 2102749681 is about 1281.1378393477.

The spelling of 2102749681 in words is "two billion, one hundred two million, seven hundred forty-nine thousand, six hundred eighty-one".