21135072424 has 32 divisors (see below), whose sum is σ = 40485070080. Its totient is φ = 10339205824.

The previous prime is 21135072419. The next prime is 21135072433. The reversal of 21135072424 is 42427053112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1374909 + ... + 1390195.

It is an arithmetic number, because the mean of its divisors is an integer number (1265158440).

Almost surely, 2^21135072424 is an apocalyptic number.

It is an amenable number.

21135072424 is a deficient number, since it is larger than the sum of its proper divisors (19349997656).

21135072424 is a wasteful number, since it uses less digits than its factorization.

21135072424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19017 (or 19013 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 31.

The spelling of 21135072424 in words is "twenty-one billion, one hundred thirty-five million, seventy-two thousand, four hundred twenty-four".