16640773657 has 2 divisors, whose sum is σ = 16640773658. Its totient is φ = 16640773656.

The previous prime is 16640773621. The next prime is 16640773687. The reversal of 16640773657 is 75637704661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8469336841 + 8171436816 = 92029^2 + 90396^2 .

It is an emirp because it is prime and its reverse (75637704661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16640773657 - 2⁷ = 16640773529 is a prime.

It is not a weakly prime, because it can be changed into another prime (16640773687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8320386828 + 8320386829.

It is an arithmetic number, because the mean of its divisors is an integer number (8320386829).

Almost surely, 2^16640773657 is an apocalyptic number.

It is an amenable number.

16640773657 is a deficient number, since it is larger than the sum of its proper divisors (1).

16640773657 is an equidigital number, since it uses as much as digits as its factorization.

16640773657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4445280, while the sum is 52.

The spelling of 16640773657 in words is "sixteen billion, six hundred forty million, seven hundred seventy-three thousand, six hundred fifty-seven".