21811438081883 has 2 divisors, whose sum is σ = 21811438081884. Its totient is φ = 21811438081882.

The previous prime is 21811438081871. The next prime is 21811438081949. The reversal of 21811438081883 is 38818083411812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21811438081883 - 2¹⁸ = 21811437819739 is a prime.

It is not a weakly prime, because it can be changed into another prime (21811438087883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10905719040941 + 10905719040942.

It is an arithmetic number, because the mean of its divisors is an integer number (10905719040942).

Almost surely, 2^{21811438081883} is an apocalyptic number.

21811438081883 is a deficient number, since it is larger than the sum of its proper divisors (1).

21811438081883 is an equidigital number, since it uses as much as digits as its factorization.

21811438081883 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2359296, while the sum is 56.

The spelling of 21811438081883 in words is "twenty-one trillion, eight hundred eleven billion, four hundred thirty-eight million, eighty-one thousand, eight hundred eighty-three".