16669657 has 4 divisors (see below), whose sum is σ = 17076276. Its totient is φ = 16263040.

The previous prime is 16669651. The next prime is 16669691. The reversal of 16669657 is 75696661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75696661 = 461 ⋅164201.

It can be written as a sum of positive squares in 2 ways, for example, as 1490841 + 15178816 = 1221^2 + 3896^2 .

It is a cyclic number.

It is not a de Polignac number, because 16669657 - 2⁷ = 16669529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16669651) 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, 203248 + ... + 203329.

It is an arithmetic number, because the mean of its divisors is an integer number (4269069).

Almost surely, 2^16669657 is an apocalyptic number.

It is an amenable number.

16669657 is a deficient number, since it is larger than the sum of its proper divisors (406619).

16669657 is an equidigital number, since it uses as much as digits as its factorization.

16669657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406618.

The product of its digits is 408240, while the sum is 46.

The square root of 16669657 is about 4082.8491277538. The cubic root of 16669657 is about 255.4517533552.

It can be divided in two parts, 166696 and 57, that added together give a triangular number (166753 = T₅₇₇).

The spelling of 16669657 in words is "sixteen million, six hundred sixty-nine thousand, six hundred fifty-seven".