21326560066 has 32 divisors (see below), whose sum is σ = 38294581248. Its totient is φ = 8709288720.

The previous prime is 21326560049. The next prime is 21326560069. The reversal of 21326560066 is 66006562312.

It is not an unprimeable number, because it can be changed into a prime (21326560069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41230 + ... + 210601.

It is an arithmetic number, because the mean of its divisors is an integer number (1196705664).

Almost surely, 2^21326560066 is an apocalyptic number.

21326560066 is a deficient number, since it is larger than the sum of its proper divisors (16968021182).

21326560066 is a wasteful number, since it uses less digits than its factorization.

21326560066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252126.

The product of its (nonzero) digits is 77760, while the sum is 37.

The spelling of 21326560066 in words is "twenty-one billion, three hundred twenty-six million, five hundred sixty thousand, sixty-six".