18861349 has 4 divisors (see below), whose sum is σ = 20312236. Its totient is φ = 17410464.

The previous prime is 18861343. The next prime is 18861377. The reversal of 18861349 is 94316881.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4368100 + 14493249 = 2090^2 + 3807^2 .

It is a cyclic number.

It is not a de Polignac number, because 18861349 - 2³ = 18861341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18861341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 725424 + ... + 725449.

It is an arithmetic number, because the mean of its divisors is an integer number (5078059).

Almost surely, 2^18861349 is an apocalyptic number.

It is an amenable number.

18861349 is a deficient number, since it is larger than the sum of its proper divisors (1450887).

18861349 is a wasteful number, since it uses less digits than its factorization.

18861349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1450886.

The product of its digits is 41472, while the sum is 40.

The square root of 18861349 is about 4342.9654615251. The cubic root of 18861349 is about 266.1894978869.

The spelling of 18861349 in words is "eighteen million, eight hundred sixty-one thousand, three hundred forty-nine".