21520002424 has 32 divisors (see below), whose sum is σ = 41263214400. Its totient is φ = 10517086720.

The previous prime is 21520002409. The next prime is 21520002451. The reversal of 21520002424 is 42420002512.

It is a super-2 number, since 2×21520002424² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21520002395 and 21520002404.

It is a congruent 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, 248532 + ... + 323740.

It is an arithmetic number, because the mean of its divisors is an integer number (1289475450).

Almost surely, 2^21520002424 is an apocalyptic number.

It is an amenable number.

21520002424 is a deficient number, since it is larger than the sum of its proper divisors (19743211976).

21520002424 is a wasteful number, since it uses less digits than its factorization.

21520002424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76023 (or 76019 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 22.

Adding to 21520002424 its reverse (42420002512), we get a palindrome (63940004936).

The spelling of 21520002424 in words is "twenty-one billion, five hundred twenty million, two thousand, four hundred twenty-four".