18681747 has 16 divisors (see below), whose sum is σ = 29386752. Its totient is φ = 10330560.

The previous prime is 18681709. The next prime is 18681749. The reversal of 18681747 is 74718681.

It is a happy number.

It is not a de Polignac number, because 18681747 - 2⁸ = 18681491 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18681699 and 18681708.

It is not an unprimeable number, because it can be changed into a prime (18681749) 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, 13698 + ... + 14999.

It is an arithmetic number, because the mean of its divisors is an integer number (1836672).

Almost surely, 2^18681747 is an apocalyptic number.

18681747 is a deficient number, since it is larger than the sum of its proper divisors (10705005).

18681747 is a wasteful number, since it uses less digits than its factorization.

18681747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28738.

The product of its digits is 75264, while the sum is 42.

The square root of 18681747 is about 4322.2386560670. The cubic root of 18681747 is about 265.3418964280.

The spelling of 18681747 in words is "eighteen million, six hundred eighty-one thousand, seven hundred forty-seven".