21793511479 has 4 divisors (see below), whose sum is σ = 21809090800. Its totient is φ = 21777932160.

The previous prime is 21793511449. The next prime is 21793511483. The reversal of 21793511479 is 97411539712.

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 21793511479 - 2¹⁷ = 21793380407 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 (21793511449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7787562 + ... + 7790359.

It is an arithmetic number, because the mean of its divisors is an integer number (5452272700).

Almost surely, 2^21793511479 is an apocalyptic number.

21793511479 is a deficient number, since it is larger than the sum of its proper divisors (15579321).

21793511479 is a wasteful number, since it uses less digits than its factorization.

21793511479 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15579320.

The product of its digits is 476280, while the sum is 49.

The spelling of 21793511479 in words is "twenty-one billion, seven hundred ninety-three million, five hundred eleven thousand, four hundred seventy-nine".