21756606356 has 48 divisors (see below), whose sum is σ = 39753806400. Its totient is φ = 10408704768.

The previous prime is 21756606329. The next prime is 21756606359. The reversal of 21756606356 is 65360665712.

It is a self number, because there is not a number n which added to its sum of digits gives 21756606356.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21756606359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7326440 + ... + 7329408.

It is an arithmetic number, because the mean of its divisors is an integer number (828204300).

Almost surely, 2^21756606356 is an apocalyptic number.

It is an amenable number.

21756606356 is a deficient number, since it is larger than the sum of its proper divisors (17997200044).

21756606356 is a wasteful number, since it uses less digits than its factorization.

21756606356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3816 (or 3814 counting only the distinct ones).

The product of its (nonzero) digits is 1360800, while the sum is 47.

The spelling of 21756606356 in words is "twenty-one billion, seven hundred fifty-six million, six hundred six thousand, three hundred fifty-six".