21642221311 has 4 divisors (see below), whose sum is σ = 21649901400. Its totient is φ = 21634541224.

The previous prime is 21642221291. The next prime is 21642221323. The reversal of 21642221311 is 11312224612.

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 21642221311 - 2¹⁵ = 21642188543 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 (21642221371) 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, 3835816 + ... + 3841453.

It is an arithmetic number, because the mean of its divisors is an integer number (5412475350).

Almost surely, 2^21642221311 is an apocalyptic number.

21642221311 is a deficient number, since it is larger than the sum of its proper divisors (7680089).

21642221311 is an equidigital number, since it uses as much as digits as its factorization.

21642221311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7680088.

The product of its digits is 1152, while the sum is 25.

Adding to 21642221311 its reverse (11312224612), we get a palindrome (32954445923).

The spelling of 21642221311 in words is "twenty-one billion, six hundred forty-two million, two hundred twenty-one thousand, three hundred eleven".