18080729 has 4 divisors (see below), whose sum is σ = 18138084. Its totient is φ = 18023376.

The previous prime is 18080681. The next prime is 18080731. The reversal of 18080729 is 92708081.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92708081 = 2083 ⋅44507.

It can be written as a sum of positive squares in 2 ways, for example, as 1081600 + 16999129 = 1040^2 + 4123^2 .

It is a cyclic number.

It is not a de Polignac number, because 18080729 - 2¹² = 18076633 is a prime.

It is a super-2 number, since 2×18080729² = 653825522342882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18080779) 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, 28202 + ... + 28835.

It is an arithmetic number, because the mean of its divisors is an integer number (4534521).

Almost surely, 2^18080729 is an apocalyptic number.

It is an amenable number.

18080729 is a deficient number, since it is larger than the sum of its proper divisors (57355).

18080729 is an equidigital number, since it uses as much as digits as its factorization.

18080729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57354.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 18080729 is about 4252.1440474189. The cubic root of 18080729 is about 262.4653511334.

It can be divided in two parts, 1808072 and 9, that added together give a palindrome (1808081).

The spelling of 18080729 in words is "eighteen million, eighty thousand, seven hundred twenty-nine".