16656580057 has 4 divisors (see below), whose sum is σ = 17937855460. Its totient is φ = 15375304656.

The previous prime is 16656579977. The next prime is 16656580069. The reversal of 16656580057 is 75008565661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75008565661 = 141041 ⋅531821.

It can be written as a sum of positive squares in 2 ways, for example, as 4034282256 + 12622297801 = 63516^2 + 112349^2 .

It is a cyclic number.

It is not a de Polignac number, because 16656580057 - 2¹⁹ = 16656055769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16656581057) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 640637682 + ... + 640637707.

It is an arithmetic number, because the mean of its divisors is an integer number (4484463865).

Almost surely, 2^16656580057 is an apocalyptic number.

It is an amenable number.

16656580057 is a deficient number, since it is larger than the sum of its proper divisors (1281275403).

16656580057 is a wasteful number, since it uses less digits than its factorization.

16656580057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1281275402.

The product of its (nonzero) digits is 1512000, while the sum is 49.

The spelling of 16656580057 in words is "sixteen billion, six hundred fifty-six million, five hundred eighty thousand, fifty-seven".