18004261 has 4 divisors (see below), whose sum is σ = 19641024. Its totient is φ = 16367500.

The previous prime is 18004249. The next prime is 18004279. The reversal of 18004261 is 16240081.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18004261 - 2⁹ = 18003749 is a prime.

It is a super-2 number, since 2×18004261² = 648306828312242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18004291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 818365 + ... + 818386.

It is an arithmetic number, because the mean of its divisors is an integer number (4910256).

Almost surely, 2^18004261 is an apocalyptic number.

18004261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18004261 is a deficient number, since it is larger than the sum of its proper divisors (1636763).

18004261 is a wasteful number, since it uses less digits than its factorization.

18004261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636762.

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

The square root of 18004261 is about 4243.1428210703. The cubic root of 18004261 is about 262.0948173802.

The spelling of 18004261 in words is "eighteen million, four thousand, two hundred sixty-one".