21493667428 has 12 divisors (see below), whose sum is σ = 37657509120. Its totient is φ = 10734379112.

The previous prime is 21493667389. The next prime is 21493667453. The reversal of 21493667428 is 82476639412.

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, 3109768 + ... + 3116671.

It is an arithmetic number, because the mean of its divisors is an integer number (3138125760).

Almost surely, 2^21493667428 is an apocalyptic number.

It is an amenable number.

21493667428 is a deficient number, since it is larger than the sum of its proper divisors (16163841692).

21493667428 is a wasteful number, since it uses less digits than its factorization.

21493667428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6227306 (or 6227304 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 52.

The spelling of 21493667428 in words is "twenty-one billion, four hundred ninety-three million, six hundred sixty-seven thousand, four hundred twenty-eight".