21128394579 has 8 divisors (see below), whose sum is σ = 28260062160. Its totient is φ = 14041161696.

The previous prime is 21128394569. The next prime is 21128394583. The reversal of 21128394579 is 97549382112.

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

It is not a de Polignac number, because 21128394579 - 2²⁴ = 21111617363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21128394569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11107564 + ... + 11109465.

It is an arithmetic number, because the mean of its divisors is an integer number (3532507770).

Almost surely, 2^21128394579 is an apocalyptic number.

21128394579 is a deficient number, since it is larger than the sum of its proper divisors (7131667581).

21128394579 is a wasteful number, since it uses less digits than its factorization.

21128394579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22217349.

The product of its digits is 1088640, while the sum is 51.

The spelling of 21128394579 in words is "twenty-one billion, one hundred twenty-eight million, three hundred ninety-four thousand, five hundred seventy-nine".