21405224524 has 12 divisors (see below), whose sum is σ = 37460962000. Its totient is φ = 10702092528.

The previous prime is 21405224509. The next prime is 21405224537. The reversal of 21405224524 is 42542250412.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28464 + ... + 208855.

Almost surely, 2^21405224524 is an apocalyptic number.

It is an amenable number.

21405224524 is a deficient number, since it is larger than the sum of its proper divisors (16055737476).

21405224524 is a wasteful number, since it uses less digits than its factorization.

21405224524 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259872 (or 259870 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 31.

Adding to 21405224524 its reverse (42542250412), we get a palindrome (63947474936).

The spelling of 21405224524 in words is "twenty-one billion, four hundred five million, two hundred twenty-four thousand, five hundred twenty-four".