21811437819739 has 2 divisors, whose sum is σ = 21811437819740. Its totient is φ = 21811437819738.

The previous prime is 21811437819713. The next prime is 21811437819757. The reversal of 21811437819739 is 93791873411812.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21811437819739 - 2¹¹ = 21811437817691 is a prime.

It is not a weakly prime, because it can be changed into another prime (21811437819709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10905718909869 + 10905718909870.

It is an arithmetic number, because the mean of its divisors is an integer number (10905718909870).

Almost surely, 2^{21811437819739} is an apocalyptic number.

21811437819739 is a deficient number, since it is larger than the sum of its proper divisors (1).

21811437819739 is an equidigital number, since it uses as much as digits as its factorization.

21811437819739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18289152, while the sum is 64.

The spelling of 21811437819739 in words is "twenty-one trillion, eight hundred eleven billion, four hundred thirty-seven million, eight hundred nineteen thousand, seven hundred thirty-nine".