21643455434613 has 16 divisors (see below), whose sum is σ = 28867839638400. Its totient is φ = 14424021622080.

The previous prime is 21643455434603. The next prime is 21643455434633. The reversal of 21643455434613 is 31643455434612.

It is a happy number.

It is not a de Polignac number, because 21643455434613 - 2²⁴ = 21643438657397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21643455434603) 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, 106274703 + ... + 106478163.

It is an arithmetic number, because the mean of its divisors is an integer number (1804239977400).

Almost surely, 2^{21643455434613} is an apocalyptic number.

It is an amenable number.

21643455434613 is a deficient number, since it is larger than the sum of its proper divisors (7224384203787).

21643455434613 is a wasteful number, since it uses less digits than its factorization.

21643455434613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215452.

The product of its digits is 12441600, while the sum is 51.

Subtracting 21643455434613 from its reverse (31643455434612), we obtain a palindrome (9999999999999).

The spelling of 21643455434613 in words is "twenty-one trillion, six hundred forty-three billion, four hundred fifty-five million, four hundred thirty-four thousand, six hundred thirteen".