18421173 has 12 divisors (see below), whose sum is σ = 26883948. Its totient is φ = 12153600.

The previous prime is 18421129. The next prime is 18421201. The reversal of 18421173 is 37112481.

It can be written as a sum of positive squares in 2 ways, for example, as 6185169 + 12236004 = 2487^2 + 3498^2 .

It is not a de Polignac number, because 18421173 - 2⁸ = 18420917 is a prime.

It is a super-2 number, since 2×18421173² = 678679229391858, which contains 22 as substring.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18421973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9678 + ... + 11423.

It is an arithmetic number, because the mean of its divisors is an integer number (2240329).

Almost surely, 2^18421173 is an apocalyptic number.

It is an amenable number.

18421173 is a deficient number, since it is larger than the sum of its proper divisors (8462775).

18421173 is a wasteful number, since it uses less digits than its factorization.

18421173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21204 (or 21201 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 18421173 is about 4291.9893988685. The cubic root of 18421173 is about 264.1024481863.

The spelling of 18421173 in words is "eighteen million, four hundred twenty-one thousand, one hundred seventy-three".