21605425264 has 20 divisors (see below), whose sum is σ = 41865474456. Its totient is φ = 10801431872.

The previous prime is 21605425241. The next prime is 21605425319. The reversal of 21605425264 is 46252450612.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 67347 + ... + 218509.

Almost surely, 2^21605425264 is an apocalyptic number.

It is an amenable number.

21605425264 is a deficient number, since it is larger than the sum of its proper divisors (20260049192).

21605425264 is a wasteful number, since it uses less digits than its factorization.

21605425264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160104 (or 160098 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 37.

Adding to 21605425264 its reverse (46252450612), we get a palindrome (67857875876).

The spelling of 21605425264 in words is "twenty-one billion, six hundred five million, four hundred twenty-five thousand, two hundred sixty-four".