21086432823 has 4 divisors (see below), whose sum is σ = 28115243768. Its totient is φ = 14057621880.

The previous prime is 21086432803. The next prime is 21086432827. The reversal of 21086432823 is 32823468012.

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

It is not a de Polignac number, because 21086432823 - 2²⁰ = 21085384247 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 (21086432827) 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, 3514405468 + ... + 3514405473.

It is an arithmetic number, because the mean of its divisors is an integer number (7028810942).

Almost surely, 2^21086432823 is an apocalyptic number.

21086432823 is a deficient number, since it is larger than the sum of its proper divisors (7028810945).

21086432823 is an equidigital number, since it uses as much as digits as its factorization.

21086432823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7028810944.

The product of its (nonzero) digits is 110592, while the sum is 39.

The spelling of 21086432823 in words is "twenty-one billion, eighty-six million, four hundred thirty-two thousand, eight hundred twenty-three".