21126684479 has 4 divisors (see below), whose sum is σ = 21127910376. Its totient is φ = 21125458584.

The previous prime is 21126684457. The next prime is 21126684529. The reversal of 21126684479 is 97448662112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21126684479 - 2¹⁶ = 21126618943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21126684379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 586724 + ... + 621689.

It is an arithmetic number, because the mean of its divisors is an integer number (5281977594).

Almost surely, 2^21126684479 is an apocalyptic number.

21126684479 is a deficient number, since it is larger than the sum of its proper divisors (1225897).

21126684479 is a wasteful number, since it uses less digits than its factorization.

21126684479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1225896.

The product of its digits is 1161216, while the sum is 50.

The spelling of 21126684479 in words is "twenty-one billion, one hundred twenty-six million, six hundred eighty-four thousand, four hundred seventy-nine".