21311881099 has 2 divisors, whose sum is σ = 21311881100. Its totient is φ = 21311881098.

The previous prime is 21311881001. The next prime is 21311881111. The reversal of 21311881099 is 99018811312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21311881099 - 2¹⁷ = 21311750027 is a prime.

It is not a weakly prime, because it can be changed into another prime (21311821099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655940549 + 10655940550.

It is an arithmetic number, because the mean of its divisors is an integer number (10655940550).

Almost surely, 2^21311881099 is an apocalyptic number.

21311881099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311881099 is an equidigital number, since it uses as much as digits as its factorization.

21311881099 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 43.

The spelling of 21311881099 in words is "twenty-one billion, three hundred eleven million, eight hundred eighty-one thousand, ninety-nine".