21155244411 has 16 divisors (see below), whose sum is σ = 33022821888. Its totient is φ = 11793864000.

The previous prime is 21155244389. The next prime is 21155244421. The reversal of 21155244411 is 11444255112.

It is not a de Polignac number, because 21155244411 - 2⁵ = 21155244379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21155244421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12284415 + ... + 12286136.

It is an arithmetic number, because the mean of its divisors is an integer number (2063926368).

Almost surely, 2^21155244411 is an apocalyptic number.

21155244411 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21155244411 is a deficient number, since it is larger than the sum of its proper divisors (11867577477).

21155244411 is a wasteful number, since it uses less digits than its factorization.

21155244411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24570602.

The product of its digits is 6400, while the sum is 30.

Adding to 21155244411 its reverse (11444255112), we get a palindrome (32599499523).

The spelling of 21155244411 in words is "twenty-one billion, one hundred fifty-five million, two hundred forty-four thousand, four hundred eleven".