21666324230653 has 4 divisors (see below), whose sum is σ = 21680365919968. Its totient is φ = 21652282541340.

The previous prime is 21666324230651. The next prime is 21666324230657. The reversal of 21666324230653 is 35603242366612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21666324230653 - 2¹ = 21666324230651 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21666324230597 and 21666324230606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21666324230651) 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, 7020842343 + ... + 7020845428.

It is an arithmetic number, because the mean of its divisors is an integer number (5420091479992).

Almost surely, 2^{21666324230653} is an apocalyptic number.

It is an amenable number.

21666324230653 is a deficient number, since it is larger than the sum of its proper divisors (14041689315).

21666324230653 is a wasteful number, since it uses less digits than its factorization.

21666324230653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14041689314.

The product of its (nonzero) digits is 5598720, while the sum is 49.

The spelling of 21666324230653 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred twenty-four million, two hundred thirty thousand, six hundred fifty-three".