21756331650 has 48 divisors (see below), whose sum is σ = 55696220928. Its totient is φ = 5614536000.

The previous prime is 21756331633. The next prime is 21756331669. The reversal of 21756331650 is 5613365712.

It is a junction number, because it is equal to n+sod(n) for n = 21756331599 and 21756331608.

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 23 ways as a sum of consecutive naturals, for example, 2334741 + ... + 2344040.

It is an arithmetic number, because the mean of its divisors is an integer number (1160337936).

Almost surely, 2^21756331650 is an apocalyptic number.

21756331650 is an abundant number, since it is smaller than the sum of its proper divisors (33939889278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21756331650 is a wasteful number, since it uses less digits than its factorization.

21756331650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4678827 (or 4678822 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 39.

The spelling of 21756331650 in words is "twenty-one billion, seven hundred fifty-six million, three hundred thirty-one thousand, six hundred fifty".