17945989 has 4 divisors (see below), whose sum is σ = 18087424. Its totient is φ = 17804556.

The previous prime is 17945981. The next prime is 17946001. The reversal of 17945989 is 98954971.

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: 98954971 = 127 ⋅779173.

It is a cyclic number.

It is not a de Polignac number, because 17945989 - 2³ = 17945981 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17945981) 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 3 ways as a sum of consecutive naturals, for example, 70527 + ... + 70780.

It is an arithmetic number, because the mean of its divisors is an integer number (4521856).

Almost surely, 2^17945989 is an apocalyptic number.

It is an amenable number.

17945989 is a deficient number, since it is larger than the sum of its proper divisors (141435).

17945989 is a wasteful number, since it uses less digits than its factorization.

17945989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141434.

The product of its digits is 816480, while the sum is 52.

The square root of 17945989 is about 4236.2706476334. The cubic root of 17945989 is about 261.8117492771.

The spelling of 17945989 in words is "seventeen million, nine hundred forty-five thousand, nine hundred eighty-nine".