10891211809 has 2 divisors, whose sum is σ = 10891211810. Its totient is φ = 10891211808.

The previous prime is 10891211801. The next prime is 10891211819. The reversal of 10891211809 is 90811219801.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10885792225 + 5419584 = 104335^2 + 2328^2 .

It is a cyclic number.

It is not a de Polignac number, because 10891211809 - 2³ = 10891211801 is a prime.

It is not a weakly prime, because it can be changed into another prime (10891211801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5445605904 + 5445605905.

It is an arithmetic number, because the mean of its divisors is an integer number (5445605905).

Almost surely, 2^10891211809 is an apocalyptic number.

It is an amenable number.

10891211809 is a deficient number, since it is larger than the sum of its proper divisors (1).

10891211809 is an equidigital number, since it uses as much as digits as its factorization.

10891211809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 40.

The spelling of 10891211809 in words is "ten billion, eight hundred ninety-one million, two hundred eleven thousand, eight hundred nine".