21244131541 has 4 divisors (see below), whose sum is σ = 21245451084. Its totient is φ = 21242812000.

The previous prime is 21244131527. The next prime is 21244131547. The reversal of 21244131541 is 14513144212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18024136516 + 3219995025 = 134254^2 + 56745^2 .

It is a cyclic number.

It is not a de Polignac number, because 21244131541 - 2¹¹ = 21244129493 is a prime.

It is a super-2 number, since 2×21244131541² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244131547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 635320 + ... + 667921.

It is an arithmetic number, because the mean of its divisors is an integer number (5311362771).

Almost surely, 2^21244131541 is an apocalyptic number.

It is an amenable number.

21244131541 is a deficient number, since it is larger than the sum of its proper divisors (1319543).

21244131541 is a wasteful number, since it uses less digits than its factorization.

21244131541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1319542.

The product of its digits is 3840, while the sum is 28.

Adding to 21244131541 its reverse (14513144212), we get a palindrome (35757275753).

The spelling of 21244131541 in words is "twenty-one billion, two hundred forty-four million, one hundred thirty-one thousand, five hundred forty-one".