21003432424 has 16 divisors (see below), whose sum is σ = 42410777220. Its totient is φ = 9693891840.

The previous prime is 21003432421. The next prime is 21003432581. The reversal of 21003432424 is 42423430012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20654863524 + 348568900 = 143718^2 + 18670^2 .

It is a super-3 number, since 3×21003432424³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21003432421) 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, 100977937 + ... + 100978144.

Almost surely, 2^21003432424 is an apocalyptic number.

It is an amenable number.

21003432424 is an abundant number, since it is smaller than the sum of its proper divisors (21407344796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21003432424 is a wasteful number, since it uses less digits than its factorization.

21003432424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201956100 (or 201956096 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21003432424 its reverse (42423430012), we get a palindrome (63426862436).

The spelling of 21003432424 in words is "twenty-one billion, three million, four hundred thirty-two thousand, four hundred twenty-four".