21144113241221 has 8 divisors (see below), whose sum is σ = 21719116769784. Its totient is φ = 20569296081600.

The previous prime is 21144113241133. The next prime is 21144113241259. The reversal of 21144113241221 is 12214231144112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 10460301909121 + 10683811332100 = 3234239^2 + 3268610^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21144113241221 - 2²² = 21144109046917 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 (21144113241521) 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, 46362230 + ... + 46816071.

It is an arithmetic number, because the mean of its divisors is an integer number (2714889596223).

Almost surely, 2^{21144113241221} is an apocalyptic number.

It is an amenable number.

21144113241221 is a deficient number, since it is larger than the sum of its proper divisors (575003528563).

21144113241221 is an equidigital number, since it uses as much as digits as its factorization.

21144113241221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93184471.

The product of its digits is 3072, while the sum is 29.

Adding to 21144113241221 its reverse (12214231144112), we get a palindrome (33358344385333).

The spelling of 21144113241221 in words is "twenty-one trillion, one hundred forty-four billion, one hundred thirteen million, two hundred forty-one thousand, two hundred twenty-one".