18418973 has 8 divisors (see below), whose sum is σ = 20175480. Its totient is φ = 16737280.

The previous prime is 18418969. The next prime is 18418979. The reversal of 18418973 is 37981481.

It can be written as a sum of positive squares in 4 ways, for example, as 6770404 + 11648569 = 2602^2 + 3413^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18418973 - 2² = 18418969 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18418973.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18418979) 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, 18188 + ... + 19173.

It is an arithmetic number, because the mean of its divisors is an integer number (2521935).

Almost surely, 2^18418973 is an apocalyptic number.

It is an amenable number.

18418973 is a deficient number, since it is larger than the sum of its proper divisors (1756507).

18418973 is a wasteful number, since it uses less digits than its factorization.

18418973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37407.

The product of its digits is 48384, while the sum is 41.

The square root of 18418973 is about 4291.7330998094. The cubic root of 18418973 is about 264.0919340438.

It can be divided in two parts, 18418 and 973, that added together give a palindrome (19391).

The spelling of 18418973 in words is "eighteen million, four hundred eighteen thousand, nine hundred seventy-three".