18251408 has 40 divisors (see below), whose sum is σ = 40890240. Its totient is φ = 7729920.

The previous prime is 18251399. The next prime is 18251413. The reversal of 18251408 is 80415281.

It is a super-2 number, since 2×18251408² = 666227787964928, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9053 + ... + 10883.

It is an arithmetic number, because the mean of its divisors is an integer number (1022256).

Almost surely, 2^18251408 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 18251408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20445120).

18251408 is an abundant number, since it is smaller than the sum of its proper divisors (22638832).

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

18251408 is a wasteful number, since it uses less digits than its factorization.

18251408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1935 (or 1929 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 29.

The square root of 18251408 is about 4272.1666634156. The cubic root of 18251408 is about 263.2886420267.

Adding to 18251408 its reverse (80415281), we get a palindrome (98666689).

The spelling of 18251408 in words is "eighteen million, two hundred fifty-one thousand, four hundred eight".