21144143444 has 6 divisors (see below), whose sum is σ = 37002251034. Its totient is φ = 10572071720.

The previous prime is 21144143429. The next prime is 21144143453. The reversal of 21144143444 is 44434144112.

It can be written as a sum of positive squares in only one way, i.e., 14015718544 + 7128424900 = 118388^2 + 84430^2 .

It is a super-2 number, since 2×21144143444² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21144143444.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2643017927 + ... + 2643017934.

It is an arithmetic number, because the mean of its divisors is an integer number (6167041839).

Almost surely, 2^21144143444 is an apocalyptic number.

It is an amenable number.

21144143444 is a deficient number, since it is larger than the sum of its proper divisors (15858107590).

21144143444 is a wasteful number, since it uses less digits than its factorization.

21144143444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5286035865 (or 5286035863 counting only the distinct ones).

The product of its digits is 24576, while the sum is 32.

Adding to 21144143444 its reverse (44434144112), we get a palindrome (65578287556).

The spelling of 21144143444 in words is "twenty-one billion, one hundred forty-four million, one hundred forty-three thousand, four hundred forty-four".