21131444211 has 8 divisors (see below), whose sum is σ = 28238861760. Its totient is φ = 14055828072.

The previous prime is 21131444209. The next prime is 21131444233. The reversal of 21131444211 is 11244413112.

It is a happy number.

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

It is not a de Polignac number, because 21131444211 - 2¹ = 21131444209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21131444251) 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, 7948801 + ... + 7951458.

It is an arithmetic number, because the mean of its divisors is an integer number (3529857720).

Almost surely, 2^21131444211 is an apocalyptic number.

21131444211 is a deficient number, since it is larger than the sum of its proper divisors (7107417549).

21131444211 is a wasteful number, since it uses less digits than its factorization.

21131444211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15900705.

The product of its digits is 768, while the sum is 24.

Adding to 21131444211 its reverse (11244413112), we get a palindrome (32375857323).

The spelling of 21131444211 in words is "twenty-one billion, one hundred thirty-one million, four hundred forty-four thousand, two hundred eleven".