17138987 has 4 divisors (see below), whose sum is σ = 17420016. Its totient is φ = 16857960.

The previous prime is 17138959. The next prime is 17139037. The reversal of 17138987 is 78983171.

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

It is not a de Polignac number, because 17138987 - 2⁶ = 17138923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17138917) 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, 140423 + ... + 140544.

It is an arithmetic number, because the mean of its divisors is an integer number (4355004).

Almost surely, 2^17138987 is an apocalyptic number.

17138987 is a deficient number, since it is larger than the sum of its proper divisors (281029).

17138987 is an equidigital number, since it uses as much as digits as its factorization.

17138987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281028.

The product of its digits is 84672, while the sum is 44.

The square root of 17138987 is about 4139.9259655216. The cubic root of 17138987 is about 257.8269927598.

The spelling of 17138987 in words is "seventeen million, one hundred thirty-eight thousand, nine hundred eighty-seven".