18681729 has 16 divisors (see below), whose sum is σ = 27312384. Its totient is φ = 11264400.

The previous prime is 18681709. The next prime is 18681749. The reversal of 18681729 is 92718681.

It is an interprime number because it is at equal distance from previous prime (18681709) and next prime (18681749).

It is not a de Polignac number, because 18681729 - 2⁵ = 18681697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18681709) 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 15 ways as a sum of consecutive naturals, for example, 5622 + ... + 8304.

It is an arithmetic number, because the mean of its divisors is an integer number (1707024).

Almost surely, 2^18681729 is an apocalyptic number.

It is an amenable number.

18681729 is a deficient number, since it is larger than the sum of its proper divisors (8630655).

18681729 is a wasteful number, since it uses less digits than its factorization.

18681729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2908.

The product of its digits is 48384, while the sum is 42.

The square root of 18681729 is about 4322.2365738122. The cubic root of 18681729 is about 265.3418112083.

The spelling of 18681729 in words is "eighteen million, six hundred eighty-one thousand, seven hundred twenty-nine".