21689916784 has 10 divisors (see below), whose sum is σ = 42024213800. Its totient is φ = 10844958384.

The previous prime is 21689916763. The next prime is 21689916791. The reversal of 21689916784 is 48761998612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 677809884 + ... + 677809915.

It is an arithmetic number, because the mean of its divisors is an integer number (4202421380).

Almost surely, 2^21689916784 is an apocalyptic number.

It is an amenable number.

21689916784 is a deficient number, since it is larger than the sum of its proper divisors (20334297016).

21689916784 is a wasteful number, since it uses less digits than its factorization.

21689916784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1355619807 (or 1355619801 counting only the distinct ones).

The product of its digits is 10450944, while the sum is 61.

The spelling of 21689916784 in words is "twenty-one billion, six hundred eighty-nine million, nine hundred sixteen thousand, seven hundred eighty-four".