21666805522 has 8 divisors (see below), whose sum is σ = 32748301872. Its totient is φ = 10750704900.

The previous prime is 21666805493. The next prime is 21666805577. The reversal of 21666805522 is 22550866612.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41348604 + ... + 41349127.

It is an arithmetic number, because the mean of its divisors is an integer number (4093537734).

Almost surely, 2^21666805522 is an apocalyptic number.

21666805522 is a deficient number, since it is larger than the sum of its proper divisors (11081496350).

21666805522 is a wasteful number, since it uses less digits than its factorization.

21666805522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82697864.

The product of its (nonzero) digits is 345600, while the sum is 43.

The spelling of 21666805522 in words is "twenty-one billion, six hundred sixty-six million, eight hundred five thousand, five hundred twenty-two".