21728267823 has 8 divisors (see below), whose sum is σ = 28972171008. Its totient is φ = 14484938264.

The previous prime is 21728267819. The next prime is 21728267833. The reversal of 21728267823 is 32876282712.

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

It is a cyclic number.

It is not a de Polignac number, because 21728267823 - 2² = 21728267819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21728267833) 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, 45465 + ... + 213362.

It is an arithmetic number, because the mean of its divisors is an integer number (3621521376).

Almost surely, 2^21728267823 is an apocalyptic number.

21728267823 is a deficient number, since it is larger than the sum of its proper divisors (7243903185).

21728267823 is a wasteful number, since it uses less digits than its factorization.

21728267823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 286813.

The product of its digits is 903168, while the sum is 48.

The spelling of 21728267823 in words is "twenty-one billion, seven hundred twenty-eight million, two hundred sixty-seven thousand, eight hundred twenty-three".