18672749 has 4 divisors (see below), whose sum is σ = 19771164. Its totient is φ = 17574336.

The previous prime is 18672739. The next prime is 18672761. The reversal of 18672749 is 94727681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15721225 + 2951524 = 3965^2 + 1718^2 .

It is a cyclic number.

It is not a de Polignac number, because 18672749 - 2²⁴ = 1895533 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18672739) 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, 549182 + ... + 549215.

It is an arithmetic number, because the mean of its divisors is an integer number (4942791).

Almost surely, 2^18672749 is an apocalyptic number.

It is an amenable number.

18672749 is a deficient number, since it is larger than the sum of its proper divisors (1098415).

18672749 is a wasteful number, since it uses less digits than its factorization.

18672749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1098414.

The product of its digits is 169344, while the sum is 44.

The square root of 18672749 is about 4321.1976349156. The cubic root of 18672749 is about 265.2992892456.

The spelling of 18672749 in words is "eighteen million, six hundred seventy-two thousand, seven hundred forty-nine".