16661677 has 4 divisors (see below), whose sum is σ = 16671420. Its totient is φ = 16651936.

The previous prime is 16661629. The next prime is 16661681. The reversal of 16661677 is 77616661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 77616661 = 307 ⋅252823.

It can be written as a sum of positive squares in 2 ways, for example, as 12524521 + 4137156 = 3539^2 + 2034^2 .

It is a cyclic number.

It is not a de Polignac number, because 16661677 - 2¹⁹ = 16137389 is a prime.

It is a super-2 number, since 2×16661677² = 555222960904658, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16664677) 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, 1552 + ... + 5977.

It is an arithmetic number, because the mean of its divisors is an integer number (4167855).

Almost surely, 2^16661677 is an apocalyptic number.

It is an amenable number.

16661677 is a deficient number, since it is larger than the sum of its proper divisors (9743).

16661677 is an equidigital number, since it uses as much as digits as its factorization.

16661677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9742.

The product of its digits is 63504, while the sum is 40.

The square root of 16661677 is about 4081.8717520275. The cubic root of 16661677 is about 255.4109840627.

The spelling of 16661677 in words is "sixteen million, six hundred sixty-one thousand, six hundred seventy-seven".