16688657 has 4 divisors (see below), whose sum is σ = 16876260. Its totient is φ = 16501056.

The previous prime is 16688647. The next prime is 16688677. The reversal of 16688657 is 75688661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9339136 + 7349521 = 3056^2 + 2711^2 .

It is a cyclic number.

It is not a de Polignac number, because 16688657 - 2¹⁴ = 16672273 is a prime.

It is a super-2 number, since 2×16688657² = 557022544927298, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (16688627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93668 + ... + 93845.

It is an arithmetic number, because the mean of its divisors is an integer number (4219065).

Almost surely, 2^16688657 is an apocalyptic number.

It is an amenable number.

16688657 is a deficient number, since it is larger than the sum of its proper divisors (187603).

16688657 is an equidigital number, since it uses as much as digits as its factorization.

16688657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187602.

The product of its digits is 483840, while the sum is 47.

The square root of 16688657 is about 4085.1752716377. The cubic root of 16688657 is about 255.5487707573.

The spelling of 16688657 in words is "sixteen million, six hundred eighty-eight thousand, six hundred fifty-seven".