21435321305663 has 4 divisors (see below), whose sum is σ = 21444211943208. Its totient is φ = 21426430668120.

The previous prime is 21435321305653. The next prime is 21435321305687. The reversal of 21435321305663 is 36650312353412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21435321305663 - 2²⁸ = 21435052870207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21435321305653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4445315156 + ... + 4445319977.

It is an arithmetic number, because the mean of its divisors is an integer number (5361052985802).

Almost surely, 2^{21435321305663} is an apocalyptic number.

21435321305663 is a deficient number, since it is larger than the sum of its proper divisors (8890637545).

21435321305663 is an equidigital number, since it uses as much as digits as its factorization.

21435321305663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8890637544.

The product of its (nonzero) digits is 1166400, while the sum is 44.

The spelling of 21435321305663 in words is "twenty-one trillion, four hundred thirty-five billion, three hundred twenty-one million, three hundred five thousand, six hundred sixty-three".