17994947 has 4 divisors (see below), whose sum is σ = 18777360. Its totient is φ = 17212536.

The previous prime is 17994929. The next prime is 17994953. The reversal of 17994947 is 74949971.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74949971 = 31 ⋅2417741.

It is a cyclic number.

It is not a de Polignac number, because 17994947 - 2¹² = 17990851 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 17994895 and 17994904.

It is not an unprimeable number, because it can be changed into a prime (17994997) 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, 391172 + ... + 391217.

It is an arithmetic number, because the mean of its divisors is an integer number (4694340).

Almost surely, 2^17994947 is an apocalyptic number.

17994947 is a deficient number, since it is larger than the sum of its proper divisors (782413).

17994947 is an equidigital number, since it uses as much as digits as its factorization.

17994947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782412.

The product of its digits is 571536, while the sum is 50.

The square root of 17994947 is about 4242.0451435599. The cubic root of 17994947 is about 262.0496137808.

The spelling of 17994947 in words is "seventeen million, nine hundred ninety-four thousand, nine hundred forty-seven".