18280749 has 16 divisors (see below), whose sum is σ = 25006592. Its totient is φ = 11875248.

The previous prime is 18280741. The next prime is 18280753. The reversal of 18280749 is 94708281.

It is not a de Polignac number, because 18280749 - 2³ = 18280741 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18280741) 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 15 ways as a sum of consecutive naturals, for example, 20262 + ... + 21144.

It is an arithmetic number, because the mean of its divisors is an integer number (1562912).

Almost surely, 2^18280749 is an apocalyptic number.

It is an amenable number.

18280749 is a deficient number, since it is larger than the sum of its proper divisors (6725843).

18280749 is a wasteful number, since it uses less digits than its factorization.

18280749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1056.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 18280749 is about 4275.5992562447. The cubic root of 18280749 is about 263.4296542723.

The spelling of 18280749 in words is "eighteen million, two hundred eighty thousand, seven hundred forty-nine".