18945749 has 8 divisors (see below), whose sum is σ = 19268760. Its totient is φ = 18625536.

The previous prime is 18945727. The next prime is 18945779. The reversal of 18945749 is 94754981.

It can be written as a sum of positive squares in 4 ways, for example, as 2380849 + 16564900 = 1543^2 + 4070^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18945749 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 (18945779) 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 7 ways as a sum of consecutive naturals, for example, 16217 + ... + 17345.

It is an arithmetic number, because the mean of its divisors is an integer number (2408595).

Almost surely, 2^18945749 is an apocalyptic number.

It is an amenable number.

18945749 is a deficient number, since it is larger than the sum of its proper divisors (323011).

18945749 is a wasteful number, since it uses less digits than its factorization.

18945749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1399.

The product of its digits is 362880, while the sum is 47.

The square root of 18945749 is about 4352.6714785290. The cubic root of 18945749 is about 266.5859517869.

It can be divided in two parts, 189 and 45749, that multiplied together give a triangular number (8646561 = T₄₁₅₈).

The spelling of 18945749 in words is "eighteen million, nine hundred forty-five thousand, seven hundred forty-nine".