21561550316 has 6 divisors (see below), whose sum is σ = 37732713060. Its totient is φ = 10780775156.

The previous prime is 21561550289. The next prime is 21561550333. The reversal of 21561550316 is 61305516512.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2695193786 + ... + 2695193793.

It is an arithmetic number, because the mean of its divisors is an integer number (6288785510).

Almost surely, 2^21561550316 is an apocalyptic number.

It is an amenable number.

21561550316 is a deficient number, since it is larger than the sum of its proper divisors (16171162744).

21561550316 is a wasteful number, since it uses less digits than its factorization.

21561550316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5390387583 (or 5390387581 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 35.

The spelling of 21561550316 in words is "twenty-one billion, five hundred sixty-one million, five hundred fifty thousand, three hundred sixteen".