18404149 has 4 divisors (see below), whose sum is σ = 19486764. Its totient is φ = 17321536.

The previous prime is 18404147. The next prime is 18404161. The reversal of 18404149 is 94140481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 94140481 = 569 ⋅165449.

It can be written as a sum of positive squares in 2 ways, for example, as 14303524 + 4100625 = 3782^2 + 2025^2 .

It is a cyclic number.

It is not a de Polignac number, because 18404149 - 2¹ = 18404147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18404149.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18404147) 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, 541282 + ... + 541315.

It is an arithmetic number, because the mean of its divisors is an integer number (4871691).

Almost surely, 2^18404149 is an apocalyptic number.

It is an amenable number.

18404149 is a deficient number, since it is larger than the sum of its proper divisors (1082615).

18404149 is a wasteful number, since it uses less digits than its factorization.

18404149 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082614.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 18404149 is about 4290.0057109519. The cubic root of 18404149 is about 264.0210660034.

It can be divided in two parts, 184041 and 49, that multiplied together give a square (9018009 = 3003²).

The spelling of 18404149 in words is "eighteen million, four hundred four thousand, one hundred forty-nine".