18121408 has 28 divisors (see below), whose sum is σ = 36322000. Its totient is φ = 8969472.

The previous prime is 18121399. The next prime is 18121417. The reversal of 18121408 is 80412181.

It is an interprime number because it is at equal distance from previous prime (18121399) and next prime (18121417).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5218 + ... + 7966.

Almost surely, 2^18121408 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18121408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18161000).

18121408 is an abundant number, since it is smaller than the sum of its proper divisors (18200592).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18121408 is a wasteful number, since it uses less digits than its factorization.

18121408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2864 (or 2854 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 18121408 is about 4256.9247115729. The cubic root of 18121408 is about 262.6620399379.

Adding to 18121408 its reverse (80412181), we get a palindrome (98533589).

The spelling of 18121408 in words is "eighteen million, one hundred twenty-one thousand, four hundred eight".