18176989 has 4 divisors (see below), whose sum is σ = 18292924. Its totient is φ = 18061056.

The previous prime is 18176971. The next prime is 18177001. The reversal of 18176989 is 98967181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98967181 = 19 ⋅5208799.

It can be written as a sum of positive squares in 2 ways, for example, as 3392964 + 14784025 = 1842^2 + 3845^2 .

It is a cyclic number.

It is not a de Polignac number, because 18176989 - 2⁷ = 18176861 is a prime.

It is a super-2 number, since 2×18176989² = 660805858212242, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18176909) 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, 57732 + ... + 58045.

It is an arithmetic number, because the mean of its divisors is an integer number (4573231).

Almost surely, 2^18176989 is an apocalyptic number.

It is an amenable number.

18176989 is a deficient number, since it is larger than the sum of its proper divisors (115935).

18176989 is a wasteful number, since it uses less digits than its factorization.

18176989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115934.

The product of its digits is 217728, while the sum is 49.

The square root of 18176989 is about 4263.4480177434. The cubic root of 18176989 is about 262.9303067754.

The spelling of 18176989 in words is "eighteen million, one hundred seventy-six thousand, nine hundred eighty-nine".