21679827591 has 8 divisors (see below), whose sum is σ = 29578679680. Its totient is φ = 14117096952.

The previous prime is 21679827527. The next prime is 21679827599. The reversal of 21679827591 is 19572897612.

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

It is not a de Polignac number, because 21679827591 - 2⁶ = 21679827527 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 (21679827599) 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, 84030211 + ... + 84030468.

It is an arithmetic number, because the mean of its divisors is an integer number (3697334960).

Almost surely, 2^21679827591 is an apocalyptic number.

21679827591 is a deficient number, since it is larger than the sum of its proper divisors (7898852089).

21679827591 is a wasteful number, since it uses less digits than its factorization.

21679827591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168060725.

The product of its digits is 3810240, while the sum is 57.

The spelling of 21679827591 in words is "twenty-one billion, six hundred seventy-nine million, eight hundred twenty-seven thousand, five hundred ninety-one".