2105346721 has 2 divisors, whose sum is σ = 2105346722. Its totient is φ = 2105346720.

The previous prime is 2105346713. The next prime is 2105346767. The reversal of 2105346721 is 1276435012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1588421025 + 516925696 = 39855^2 + 22736^2 .

It is a cyclic number.

It is not a de Polignac number, because 2105346721 - 2³ = 2105346713 is a prime.

It is not a weakly prime, because it can be changed into another prime (2105346701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1052673360 + 1052673361.

It is an arithmetic number, because the mean of its divisors is an integer number (1052673361).

Almost surely, 2^2105346721 is an apocalyptic number.

It is an amenable number.

2105346721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2105346721 is an equidigital number, since it uses as much as digits as its factorization.

2105346721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 2105346721 is about 45884.0573729046. The cubic root of 2105346721 is about 1281.6650533767.

The spelling of 2105346721 in words is "two billion, one hundred five million, three hundred forty-six thousand, seven hundred twenty-one".