18561481 has 4 divisors (see below), whose sum is σ = 18590992. Its totient is φ = 18531972.

The previous prime is 18561443. The next prime is 18561503. The reversal of 18561481 is 18416581.

It is a happy number.

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 18561481 - 2¹³ = 18553289 is a prime.

It is a super-2 number, since 2×18561481² = 689057153826722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18561401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13791 + ... + 15076.

It is an arithmetic number, because the mean of its divisors is an integer number (4647748).

Almost surely, 2^18561481 is an apocalyptic number.

It is an amenable number.

18561481 is a deficient number, since it is larger than the sum of its proper divisors (29511).

18561481 is an equidigital number, since it uses as much as digits as its factorization.

18561481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29510.

The product of its digits is 7680, while the sum is 34.

The square root of 18561481 is about 4308.3037265263. The cubic root of 18561481 is about 264.7712800440.

The spelling of 18561481 in words is "eighteen million, five hundred sixty-one thousand, four hundred eighty-one".