21605546611223 has 2 divisors, whose sum is σ = 21605546611224. Its totient is φ = 21605546611222.

The previous prime is 21605546611199. The next prime is 21605546611279. The reversal of 21605546611223 is 32211664550612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21605546611223 - 2²² = 21605542416919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21605546617223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10802773305611 + 10802773305612.

It is an arithmetic number, because the mean of its divisors is an integer number (10802773305612).

Almost surely, 2^{21605546611223} is an apocalyptic number.

21605546611223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21605546611223 is an equidigital number, since it uses as much as digits as its factorization.

21605546611223 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 518400, while the sum is 44.

The spelling of 21605546611223 in words is "twenty-one trillion, six hundred five billion, five hundred forty-six million, six hundred eleven thousand, two hundred twenty-three".