18491149 has 4 divisors (see below), whose sum is σ = 19295136. Its totient is φ = 17687164.

The previous prime is 18491147. The next prime is 18491173. The reversal of 18491149 is 94119481.

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, and also an emirpimes, since its reverse is a distinct semiprime: 94119481 = 1811 ⋅51971.

It is a cyclic number.

It is not a de Polignac number, because 18491149 - 2¹ = 18491147 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 (18491147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 401959 + ... + 402004.

It is an arithmetic number, because the mean of its divisors is an integer number (4823784).

Almost surely, 2^18491149 is an apocalyptic number.

It is an amenable number.

18491149 is a deficient number, since it is larger than the sum of its proper divisors (803987).

18491149 is an equidigital number, since it uses as much as digits as its factorization.

18491149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803986.

The product of its digits is 10368, while the sum is 37.

The square root of 18491149 is about 4300.1336025756. The cubic root of 18491149 is about 264.4364385227.

The spelling of 18491149 in words is "eighteen million, four hundred ninety-one thousand, one hundred forty-nine".