16678657 has 4 divisors (see below), whose sum is σ = 17403840. Its totient is φ = 15953476.

The previous prime is 16678639. The next prime is 16678661. The reversal of 16678657 is 75687661.

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: 75687661 = 7 ⋅10812523.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16678657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16678357) 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, 362557 + ... + 362602.

It is an arithmetic number, because the mean of its divisors is an integer number (4350960).

Almost surely, 2^16678657 is an apocalyptic number.

It is an amenable number.

16678657 is a deficient number, since it is larger than the sum of its proper divisors (725183).

16678657 is an equidigital number, since it uses as much as digits as its factorization.

16678657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725182.

The product of its digits is 423360, while the sum is 46.

The square root of 16678657 is about 4083.9511505404. The cubic root of 16678657 is about 255.4977181511.

The spelling of 16678657 in words is "sixteen million, six hundred seventy-eight thousand, six hundred fifty-seven".