21516440546 has 8 divisors (see below), whose sum is σ = 32297187564. Its totient is φ = 10750711360.

The previous prime is 21516440521. The next prime is 21516440557. The reversal of 21516440546 is 64504461512.

It is a happy number.

21516440546 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 20933749225 + 582691321 = 144685^2 + 24139^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3750875 + ... + 3756606.

Almost surely, 2^21516440546 is an apocalyptic number.

21516440546 is a deficient number, since it is larger than the sum of its proper divisors (10780747018).

21516440546 is a wasteful number, since it uses less digits than its factorization.

21516440546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7508916.

The product of its (nonzero) digits is 115200, while the sum is 38.

The spelling of 21516440546 in words is "twenty-one billion, five hundred sixteen million, four hundred forty thousand, five hundred forty-six".