21144105540121 has 16 divisors (see below), whose sum is σ = 22105637751168. Its totient is φ = 20186096832000.

The previous prime is 21144105540113. The next prime is 21144105540149. The reversal of 21144105540121 is 12104550144112.

It is not a de Polignac number, because 21144105540121 - 2³ = 21144105540113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21144105540221) 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, 228917470 + ... + 229009816.

It is an arithmetic number, because the mean of its divisors is an integer number (1381602359448).

Almost surely, 2^{21144105540121} is an apocalyptic number.

It is an amenable number.

21144105540121 is a deficient number, since it is larger than the sum of its proper divisors (961532211047).

21144105540121 is a wasteful number, since it uses less digits than its factorization.

21144105540121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111312.

The product of its (nonzero) digits is 6400, while the sum is 31.

Adding to 21144105540121 its reverse (12104550144112), we get a palindrome (33248655684233).

The spelling of 21144105540121 in words is "twenty-one trillion, one hundred forty-four billion, one hundred five million, five hundred forty thousand, one hundred twenty-one".