21521044523011 has 32 divisors (see below), whose sum is σ = 25048629236736. Its totient is φ = 18450373110400.

The previous prime is 21521044523009. The next prime is 21521044523029. The reversal of 21521044523011 is 11032544012512.

It is not a de Polignac number, because 21521044523011 - 2¹ = 21521044523009 is a prime.

It is a super-2 number, since 2×21521044523011² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21521044523081) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2777206 + ... + 7124251.

It is an arithmetic number, because the mean of its divisors is an integer number (782769663648).

Almost surely, 2^{21521044523011} is an apocalyptic number.

21521044523011 is a deficient number, since it is larger than the sum of its proper divisors (3527584713725).

21521044523011 is an equidigital number, since it uses as much as digits as its factorization.

21521044523011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9901584 (or 9901562 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 31.

Adding to 21521044523011 its reverse (11032544012512), we get a palindrome (32553588535523).

The spelling of 21521044523011 in words is "twenty-one trillion, five hundred twenty-one billion, forty-four million, five hundred twenty-three thousand, eleven".