21000133424 has 40 divisors (see below), whose sum is σ = 40976395200. Its totient is φ = 10425835008.

The previous prime is 21000133423. The next prime is 21000133499. The reversal of 21000133424 is 42433100012.

It is a junction number, because it is equal to n+sod(n) for n = 21000133396 and 21000133405.

It is not an unprimeable number, because it can be changed into a prime (21000133423) 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 7 ways as a sum of consecutive naturals, for example, 1360502 + ... + 1375850.

It is an arithmetic number, because the mean of its divisors is an integer number (1024409880).

Almost surely, 2^21000133424 is an apocalyptic number.

It is an amenable number.

21000133424 is a deficient number, since it is larger than the sum of its proper divisors (19976261776).

21000133424 is a wasteful number, since it uses less digits than its factorization.

21000133424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15957 (or 15951 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21000133424 its reverse (42433100012), we get a palindrome (63433233436).

The spelling of 21000133424 in words is "twenty-one billion, one hundred thirty-three thousand, four hundred twenty-four".