18172408 has 8 divisors (see below), whose sum is σ = 34073280. Its totient is φ = 9086200.

The previous prime is 18172391. The next prime is 18172423. The reversal of 18172408 is 80427181.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 18172408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1135768 + ... + 1135783.

It is an arithmetic number, because the mean of its divisors is an integer number (4259160).

Almost surely, 2^18172408 is an apocalyptic number.

It is an amenable number.

18172408 is a deficient number, since it is larger than the sum of its proper divisors (15900872).

18172408 is a wasteful number, since it uses less digits than its factorization.

18172408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2271557 (or 2271553 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 18172408 is about 4262.9107426734. The cubic root of 18172408 is about 262.9082168511.

Adding to 18172408 its reverse (80427181), we get a palindrome (98599589).

It can be divided in two parts, 1817 and 2408, that added together give a square (4225 = 65²).

The spelling of 18172408 in words is "eighteen million, one hundred seventy-two thousand, four hundred eight".