16687121 has 8 divisors (see below), whose sum is σ = 18995904. Its totient is φ = 14510320.

The previous prime is 16687117. The next prime is 16687129. The reversal of 16687121 is 12178661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 16687121 - 2² = 16687117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16687129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32726 + ... + 33231.

It is an arithmetic number, because the mean of its divisors is an integer number (2374488).

Almost surely, 2^16687121 is an apocalyptic number.

16687121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16687121 is a deficient number, since it is larger than the sum of its proper divisors (2308783).

16687121 is a wasteful number, since it uses less digits than its factorization.

16687121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65991.

The product of its digits is 4032, while the sum is 32.

The square root of 16687121 is about 4084.9872704820. The cubic root of 16687121 is about 255.5409304030.

The spelling of 16687121 in words is "sixteen million, six hundred eighty-seven thousand, one hundred twenty-one".