18681445 has 8 divisors (see below), whose sum is σ = 22964760. Its totient is φ = 14580480.

The previous prime is 18681431. The next prime is 18681463. The reversal of 18681445 is 54418681.

It can be written as a sum of positive squares in 4 ways, for example, as 10404 + 18671041 = 102^2 + 4321^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18681445 - 2¹⁷ = 18550373 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45360 + ... + 45769.

It is an arithmetic number, because the mean of its divisors is an integer number (2870595).

Almost surely, 2^18681445 is an apocalyptic number.

It is an amenable number.

18681445 is a deficient number, since it is larger than the sum of its proper divisors (4283315).

18681445 is an equidigital number, since it uses as much as digits as its factorization.

18681445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91175.

The product of its digits is 30720, while the sum is 37.

The square root of 18681445 is about 4322.2037203260. The cubic root of 18681445 is about 265.3404666244.

The spelling of 18681445 in words is "eighteen million, six hundred eighty-one thousand, four hundred forty-five".