21003144424 has 16 divisors (see below), whose sum is σ = 40445244900. Its totient is φ = 10217745792.

The previous prime is 21003144403. The next prime is 21003144427. The reversal of 21003144424 is 42444130012.

It can be written as a sum of positive squares in 2 ways, for example, as 19401704100 + 1601440324 = 139290^2 + 40018^2 .

It is a super-2 number, since 2×21003144424² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21003144427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35477989 + ... + 35478580.

Almost surely, 2^21003144424 is an apocalyptic number.

It is an amenable number.

21003144424 is a deficient number, since it is larger than the sum of its proper divisors (19442100476).

21003144424 is a wasteful number, since it uses less digits than its factorization.

21003144424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70956612 (or 70956608 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 21003144424 its reverse (42444130012), we get a palindrome (63447274436).

The spelling of 21003144424 in words is "twenty-one billion, three million, one hundred forty-four thousand, four hundred twenty-four".