18012261 has 4 divisors (see below), whose sum is σ = 24016352. Its totient is φ = 12008172.

The previous prime is 18012259. The next prime is 18012307. The reversal of 18012261 is 16221081.

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 not a de Polignac number, because 18012261 - 2¹ = 18012259 is a prime.

It is a super-3 number, since 3×18012261³ (a number of 23 digits) contains 333 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 (18012251) 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, 3002041 + ... + 3002046.

It is an arithmetic number, because the mean of its divisors is an integer number (6004088).

Almost surely, 2^18012261 is an apocalyptic number.

It is an amenable number.

18012261 is a deficient number, since it is larger than the sum of its proper divisors (6004091).

18012261 is an equidigital number, since it uses as much as digits as its factorization.

18012261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6004090.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 18012261 is about 4244.0854138436. The cubic root of 18012261 is about 262.1336313043.

The spelling of 18012261 in words is "eighteen million, twelve thousand, two hundred sixty-one".