21668924488 has 8 divisors (see below), whose sum is σ = 40629233430. Its totient is φ = 10834462240.

The previous prime is 21668924483. The next prime is 21668924521. The reversal of 21668924488 is 88442986612.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21297899844 + 371024644 = 145938^2 + 19262^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (21668924483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1354307773 + ... + 1354307788.

Almost surely, 2^21668924488 is an apocalyptic number.

It is an amenable number.

21668924488 is a deficient number, since it is larger than the sum of its proper divisors (18960308942).

21668924488 is a wasteful number, since it uses less digits than its factorization.

21668924488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708615567 (or 2708615563 counting only the distinct ones).

The product of its digits is 10616832, while the sum is 58.

The spelling of 21668924488 in words is "twenty-one billion, six hundred sixty-eight million, nine hundred twenty-four thousand, four hundred eighty-eight".