16506618721 has 16 divisors (see below), whose sum is σ = 17247859200. Its totient is φ = 15777115200.

The previous prime is 16506618703. The next prime is 16506618731. The reversal of 16506618721 is 12781660561.

It is a cyclic number.

It is not a de Polignac number, because 16506618721 - 2¹¹ = 16506616673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16506618731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5912836 + ... + 5915626.

It is an arithmetic number, because the mean of its divisors is an integer number (1077991200).

Almost surely, 2^16506618721 is an apocalyptic number.

It is an amenable number.

16506618721 is a deficient number, since it is larger than the sum of its proper divisors (741240479).

16506618721 is a wasteful number, since it uses less digits than its factorization.

16506618721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4800.

The product of its (nonzero) digits is 120960, while the sum is 43.

The spelling of 16506618721 in words is "sixteen billion, five hundred six million, six hundred eighteen thousand, seven hundred twenty-one".