21311755559 has 2 divisors, whose sum is σ = 21311755560. Its totient is φ = 21311755558.

The previous prime is 21311755547. The next prime is 21311755613. The reversal of 21311755559 is 95555711312.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311755559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311755459) 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, 10655877779 + 10655877780.

It is an arithmetic number, because the mean of its divisors is an integer number (10655877780).

Almost surely, 2^21311755559 is an apocalyptic number.

21311755559 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311755559 is an equidigital number, since it uses as much as digits as its factorization.

21311755559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 236250, while the sum is 44.

The spelling of 21311755559 in words is "twenty-one billion, three hundred eleven million, seven hundred fifty-five thousand, five hundred fifty-nine".