21504066366 has 32 divisors (see below), whose sum is σ = 43096458240. Its totient is φ = 7153320384.

The previous prime is 21504066349. The next prime is 21504066379. The reversal of 21504066366 is 66366040512.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10033491 + ... + 10035633.

It is an arithmetic number, because the mean of its divisors is an integer number (1346764320).

Almost surely, 2^21504066366 is an apocalyptic number.

21504066366 is an abundant number, since it is smaller than the sum of its proper divisors (21592391874).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21504066366 is a wasteful number, since it uses less digits than its factorization.

21504066366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4800.

The product of its (nonzero) digits is 155520, while the sum is 39.

The spelling of 21504066366 in words is "twenty-one billion, five hundred four million, sixty-six thousand, three hundred sixty-six".