21126491559 has 6 divisors (see below), whose sum is σ = 30516043376. Its totient is φ = 14084327700.

The previous prime is 21126491459. The next prime is 21126491563. The reversal of 21126491559 is 95519462112.

21126491559 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 6 + 4 + 91 + 559 = 666.

It is not a de Polignac number, because 21126491559 - 2¹⁹ = 21125967271 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 (21126491359) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1173693967 + ... + 1173693984.

Almost surely, 2^21126491559 is an apocalyptic number.

21126491559 is a deficient number, since it is larger than the sum of its proper divisors (9389551817).

21126491559 is a wasteful number, since it uses less digits than its factorization.

21126491559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2347387957 (or 2347387954 counting only the distinct ones).

The product of its digits is 194400, while the sum is 45.

The spelling of 21126491559 in words is "twenty-one billion, one hundred twenty-six million, four hundred ninety-one thousand, five hundred fifty-nine".