18404101 has 4 divisors (see below), whose sum is σ = 18593932. Its totient is φ = 18214272.

The previous prime is 18404083. The next prime is 18404137. The reversal of 18404101 is 10140481.

It is a Cunningham number, because it is equal to 4290²+1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10140481 = 13 ⋅780037.

It can be written as a sum of positive squares in 2 ways, for example, as 8259876 + 10144225 = 2874^2 + 3185^2 .

It is not a de Polignac number, because 18404101 - 2¹⁷ = 18273029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18404161) 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, 94770 + ... + 94963.

It is an arithmetic number, because the mean of its divisors is an integer number (4648483).

Almost surely, 2^18404101 is an apocalyptic number.

It is an amenable number.

18404101 is a deficient number, since it is larger than the sum of its proper divisors (189831).

18404101 is an equidigital number, since it uses as much as digits as its factorization.

18404101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189830.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 18404101 is about 4290.0001165501. Note that the first 3 decimals coincide. The cubic root of 18404101 is about 264.0208364714.

Adding to 18404101 its reverse (10140481), we get a palindrome (28544582).

The spelling of 18404101 in words is "eighteen million, four hundred four thousand, one hundred one".