21066643055 has 8 divisors (see below), whose sum is σ = 25281724272. Its totient is φ = 16852146048.

The previous prime is 21066643007. The next prime is 21066643109. The reversal of 21066643055 is 55034666012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21066643055 - 2²⁰ = 21065594479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62357 + ... + 214526.

It is an arithmetic number, because the mean of its divisors is an integer number (3160215534).

Almost surely, 2^21066643055 is an apocalyptic number.

21066643055 is a deficient number, since it is larger than the sum of its proper divisors (4215081217).

21066643055 is a wasteful number, since it uses less digits than its factorization.

21066643055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292105.

The product of its (nonzero) digits is 129600, while the sum is 38.

The spelling of 21066643055 in words is "twenty-one billion, sixty-six million, six hundred forty-three thousand, fifty-five".