21821927927 has 4 divisors (see below), whose sum is σ = 21831212256. Its totient is φ = 21812643600.

The previous prime is 21821927921. The next prime is 21821927951. The reversal of 21821927927 is 72972912812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21821927927 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 (21821927921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4638638 + ... + 4643339.

It is an arithmetic number, because the mean of its divisors is an integer number (5457803064).

Almost surely, 2^21821927927 is an apocalyptic number.

21821927927 is a deficient number, since it is larger than the sum of its proper divisors (9284329).

21821927927 is an equidigital number, since it uses as much as digits as its factorization.

21821927927 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9284328.

The product of its digits is 508032, while the sum is 50.

The spelling of 21821927927 in words is "twenty-one billion, eight hundred twenty-one million, nine hundred twenty-seven thousand, nine hundred twenty-seven".