21244445315121 has 16 divisors (see below), whose sum is σ = 32373015283584. Its totient is φ = 12139485343104.

The previous prime is 21244445315111. The next prime is 21244445315129. The reversal of 21244445315121 is 12151354444212.

It is a happy number.

It is not a de Polignac number, because 21244445315121 - 2⁵ = 21244445315089 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21244445315121.

It is not an unprimeable number, because it can be changed into a prime (21244445315129) 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, 6912060 + ... + 9500813.

It is an arithmetic number, because the mean of its divisors is an integer number (2023313455224).

Almost surely, 2^{21244445315121} is an apocalyptic number.

21244445315121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21244445315121 is a deficient number, since it is larger than the sum of its proper divisors (11128569968463).

21244445315121 is a wasteful number, since it uses less digits than its factorization.

21244445315121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16474520.

The product of its digits is 153600, while the sum is 39.

Adding to 21244445315121 its reverse (12151354444212), we get a palindrome (33395799759333).

The spelling of 21244445315121 in words is "twenty-one trillion, two hundred forty-four billion, four hundred forty-five million, three hundred fifteen thousand, one hundred twenty-one".