16565740651 has 4 divisors (see below), whose sum is σ = 16627323600. Its totient is φ = 16504157704.

The previous prime is 16565740643. The next prime is 16565740699. The reversal of 16565740651 is 15604756561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15604756561 = 124919².

It is a cyclic number.

It is not a de Polignac number, because 16565740651 - 2³ = 16565740643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16565740621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30791071 + ... + 30791608.

It is an arithmetic number, because the mean of its divisors is an integer number (4156830900).

Almost surely, 2^16565740651 is an apocalyptic number.

16565740651 is a deficient number, since it is larger than the sum of its proper divisors (61582949).

16565740651 is an equidigital number, since it uses as much as digits as its factorization.

16565740651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61582948.

The product of its (nonzero) digits is 756000, while the sum is 46.

The spelling of 16565740651 in words is "sixteen billion, five hundred sixty-five million, seven hundred forty thousand, six hundred fifty-one".