21823131991587 has 8 divisors (see below), whose sum is σ = 29883928493136. Its totient is φ = 14155545075552.

The previous prime is 21823131991579. The next prime is 21823131991589. The reversal of 21823131991587 is 78519913132812.

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

It is not a de Polignac number, because 21823131991587 - 2³ = 21823131991579 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21823131991587.

It is not an unprimeable number, because it can be changed into a prime (21823131991589) 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, 98302396248 + ... + 98302396469.

It is an arithmetic number, because the mean of its divisors is an integer number (3735491061642).

Almost surely, 2^{21823131991587} is an apocalyptic number.

21823131991587 is a deficient number, since it is larger than the sum of its proper divisors (8060796501549).

21823131991587 is a wasteful number, since it uses less digits than its factorization.

21823131991587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196604792757.

The product of its digits is 6531840, while the sum is 60.

The spelling of 21823131991587 in words is "twenty-one trillion, eight hundred twenty-three billion, one hundred thirty-one million, nine hundred ninety-one thousand, five hundred eighty-seven".