16771661 has 4 divisors (see below), whose sum is σ = 17654400. Its totient is φ = 15888924.

The previous prime is 16771637. The next prime is 16771663. The reversal of 16771661 is 16617761.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16617761 = 19 ⋅874619.

It is a cyclic number.

It is not a de Polignac number, because 16771661 - 2¹⁸ = 16509517 is a prime.

It is a super-3 number, since 3×16771661³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16771663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 441341 + ... + 441378.

It is an arithmetic number, because the mean of its divisors is an integer number (4413600).

Almost surely, 2^16771661 is an apocalyptic number.

It is an amenable number.

16771661 is a deficient number, since it is larger than the sum of its proper divisors (882739).

16771661 is an equidigital number, since it uses as much as digits as its factorization.

16771661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 882738.

The product of its digits is 10584, while the sum is 35.

The square root of 16771661 is about 4095.3218432743. The cubic root of 16771661 is about 255.9717426900.

The spelling of 16771661 in words is "sixteen million, seven hundred seventy-one thousand, six hundred sixty-one".