16566761 has 2 divisors, whose sum is σ = 16566762. Its totient is φ = 16566760.

The previous prime is 16566757. The next prime is 16566779. The reversal of 16566761 is 16766561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16556761 + 10000 = 4069^2 + 100^2 .

It is a cyclic number.

It is not a de Polignac number, because 16566761 - 2² = 16566757 is a prime.

It is a super-2 number, since 2×16566761² = 548915140062242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16566731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8283380 + 8283381.

It is an arithmetic number, because the mean of its divisors is an integer number (8283381).

Almost surely, 2^16566761 is an apocalyptic number.

It is an amenable number.

16566761 is a deficient number, since it is larger than the sum of its proper divisors (1).

16566761 is an equidigital number, since it uses as much as digits as its factorization.

16566761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 38.

The square root of 16566761 is about 4070.2286176577. The cubic root of 16566761 is about 254.9250632041.

The spelling of 16566761 in words is "sixteen million, five hundred sixty-six thousand, seven hundred sixty-one".