21134405663 has 16 divisors (see below), whose sum is σ = 24636510720. Its totient is φ = 17753782176.

The previous prime is 21134405647. The next prime is 21134405681. The reversal of 21134405663 is 36650443112.

It is a cyclic number.

It is not a de Polignac number, because 21134405663 - 2⁴ = 21134405647 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 (21134405263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 309956 + ... + 371942.

It is an arithmetic number, because the mean of its divisors is an integer number (1539781920).

Almost surely, 2^21134405663 is an apocalyptic number.

21134405663 is a deficient number, since it is larger than the sum of its proper divisors (3502105057).

21134405663 is an equidigital number, since it uses as much as digits as its factorization.

21134405663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62966.

The product of its (nonzero) digits is 51840, while the sum is 35.

Adding to 21134405663 its reverse (36650443112), we get a palindrome (57784848775).

The spelling of 21134405663 in words is "twenty-one billion, one hundred thirty-four million, four hundred five thousand, six hundred sixty-three".