18206401 has 4 divisors (see below), whose sum is σ = 18549972. Its totient is φ = 17862832.

The previous prime is 18206381. The next prime is 18206407. The reversal of 18206401 is 10460281.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16646400 + 1560001 = 4080^2 + 1249^2 .

It is a cyclic number.

It is not a de Polignac number, because 18206401 - 2⁵ = 18206369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18206407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171706 + ... + 171811.

It is an arithmetic number, because the mean of its divisors is an integer number (4637493).

Almost surely, 2^18206401 is an apocalyptic number.

It is an amenable number.

18206401 is a deficient number, since it is larger than the sum of its proper divisors (343571).

18206401 is an equidigital number, since it uses as much as digits as its factorization.

18206401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343570.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 18206401 is about 4266.8959443605. The cubic root of 18206401 is about 263.0720453011.

Adding to 18206401 its reverse (10460281), we get a palindrome (28666682).

The spelling of 18206401 in words is "eighteen million, two hundred six thousand, four hundred one".