21003324666 has 32 divisors (see below), whose sum is σ = 42410729088. Its totient is φ = 6934050240.

The previous prime is 21003324649. The next prime is 21003324697. The reversal of 21003324666 is 66642330012.

It is a super-2 number, since 2×21003324666² (a number of 21 digits) contains 22 as substring.

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, 257116 + ... + 328808.

It is an arithmetic number, because the mean of its divisors is an integer number (1325335284).

Almost surely, 2^21003324666 is an apocalyptic number.

21003324666 is an abundant number, since it is smaller than the sum of its proper divisors (21407404422).

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

21003324666 is a wasteful number, since it uses less digits than its factorization.

21003324666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72166.

The product of its (nonzero) digits is 31104, while the sum is 33.

Adding to 21003324666 its reverse (66642330012), we get a palindrome (87645654678).

The spelling of 21003324666 in words is "twenty-one billion, three million, three hundred twenty-four thousand, six hundred sixty-six".