21504446066 has 8 divisors (see below), whose sum is σ = 32409544944. Its totient is φ = 10701264420.

The previous prime is 21504445981. The next prime is 21504446099. The reversal of 21504446066 is 66064440512.

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

It is a Curzon number.

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, 25478780 + ... + 25479623.

It is an arithmetic number, because the mean of its divisors is an integer number (4051193118).

Almost surely, 2^21504446066 is an apocalyptic number.

21504446066 is a deficient number, since it is larger than the sum of its proper divisors (10905098878).

21504446066 is a wasteful number, since it uses less digits than its factorization.

21504446066 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50958616.

The product of its (nonzero) digits is 138240, while the sum is 38.

Adding to 21504446066 its reverse (66064440512), we get a palindrome (87568886578).

The spelling of 21504446066 in words is "twenty-one billion, five hundred four million, four hundred forty-six thousand, sixty-six".