21801727267 has 4 divisors (see below), whose sum is σ = 21802066720. Its totient is φ = 21801387816.

The previous prime is 21801727223. The next prime is 21801727273. The reversal of 21801727267 is 76272710812.

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

It is a cyclic number.

It is not a de Polignac number, because 21801727267 - 2¹⁹ = 21801202979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21801727067) 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, 40683 + ... + 212740.

It is an arithmetic number, because the mean of its divisors is an integer number (5450516680).

Almost surely, 2^21801727267 is an apocalyptic number.

21801727267 is a deficient number, since it is larger than the sum of its proper divisors (339453).

21801727267 is an equidigital number, since it uses as much as digits as its factorization.

21801727267 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339452.

The product of its (nonzero) digits is 131712, while the sum is 43.

The spelling of 21801727267 in words is "twenty-one billion, eight hundred one million, seven hundred twenty-seven thousand, two hundred sixty-seven".