18401281 has 4 divisors (see below), whose sum is σ = 18414592. Its totient is φ = 18387972.

The previous prime is 18401261. The next prime is 18401287. The reversal of 18401281 is 18210481.

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 18401281 - 2⁹ = 18400769 is a prime.

It is a super-2 number, since 2×18401281² = 677214284881922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18401287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4305 + ... + 7438.

It is an arithmetic number, because the mean of its divisors is an integer number (4603648).

Almost surely, 2^18401281 is an apocalyptic number.

It is an amenable number.

18401281 is a deficient number, since it is larger than the sum of its proper divisors (13311).

18401281 is a wasteful number, since it uses less digits than its factorization.

18401281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13310.

The product of its (nonzero) digits is 512, while the sum is 25.

The square root of 18401281 is about 4289.6714326391. The cubic root of 18401281 is about 264.0073507672.

The spelling of 18401281 in words is "eighteen million, four hundred one thousand, two hundred eighty-one".