21761225656 has 16 divisors (see below), whose sum is σ = 41376979440. Its totient is φ = 10727364480.

The previous prime is 21761225623. The next prime is 21761225659. The reversal of 21761225656 is 65652216712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21761225659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19155441 + ... + 19156576.

It is an arithmetic number, because the mean of its divisors is an integer number (2586061215).

Almost surely, 2^21761225656 is an apocalyptic number.

It is an amenable number.

21761225656 is a deficient number, since it is larger than the sum of its proper divisors (19615753784).

21761225656 is a wasteful number, since it uses less digits than its factorization.

21761225656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38312094 (or 38312090 counting only the distinct ones).

The product of its digits is 302400, while the sum is 43.

The spelling of 21761225656 in words is "twenty-one billion, seven hundred sixty-one million, two hundred twenty-five thousand, six hundred fifty-six".