16683661 has 2 divisors, whose sum is σ = 16683662. Its totient is φ = 16683660.

The previous prime is 16683643. The next prime is 16683677. The reversal of 16683661 is 16638661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14062500 + 2621161 = 3750^2 + 1619^2 .

It is a cyclic number.

It is not a de Polignac number, because 16683661 - 2⁵ = 16683629 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16683661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16683061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8341830 + 8341831.

It is an arithmetic number, because the mean of its divisors is an integer number (8341831).

Almost surely, 2^16683661 is an apocalyptic number.

It is an amenable number.

16683661 is a deficient number, since it is larger than the sum of its proper divisors (1).

16683661 is an equidigital number, since it uses as much as digits as its factorization.

16683661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 16683661 is about 4084.5637465952. The cubic root of 16683661 is about 255.5232674253.

It can be divided in two parts, 1668 and 3661, that added together give a square (5329 = 73²).

The spelling of 16683661 in words is "sixteen million, six hundred eighty-three thousand, six hundred sixty-one".