18401 has 2 divisors, whose sum is σ = 18402. Its totient is φ = 18400.

The previous prime is 18397. The next prime is 18413. The reversal of 18401 is 10481.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15376 + 3025 = 124^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 18401 - 2² = 18397 is a prime.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (18451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200 + 9201.

It is an arithmetic number, because the mean of its divisors is an integer number (9201).

2¹⁸⁴⁰¹ is an apocalyptic number.

It is an amenable number.

18401 is a deficient number, since it is larger than the sum of its proper divisors (1).

18401 is an equidigital number, since it uses as much as digits as its factorization.

18401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 18401 is about 135.6502856613. The cubic root of 18401 is about 26.4006006903.

Adding to 18401 its reverse (10481), we get a palindrome (28882).

The spelling of 18401 in words is "eighteen thousand, four hundred one".