18449661 has 4 divisors (see below), whose sum is σ = 24599552. Its totient is φ = 12299772.

The previous prime is 18449603. The next prime is 18449663. The reversal of 18449661 is 16694481.

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 not a de Polignac number, because 18449661 - 2⁷ = 18449533 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 (18449663) 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, 3074941 + ... + 3074946.

It is an arithmetic number, because the mean of its divisors is an integer number (6149888).

Almost surely, 2^18449661 is an apocalyptic number.

It is an amenable number.

18449661 is a deficient number, since it is larger than the sum of its proper divisors (6149891).

18449661 is an equidigital number, since it uses as much as digits as its factorization.

18449661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6149890.

The product of its digits is 41472, while the sum is 39.

The square root of 18449661 is about 4295.3068574899. The cubic root of 18449661 is about 264.2385212335.

It can be divided in two parts, 18449 and 661, that added together give a triangular number (19110 = T₁₉₅).

The spelling of 18449661 in words is "eighteen million, four hundred forty-nine thousand, six hundred sixty-one".