13228729 has 4 divisors (see below), whose sum is σ = 13236084. Its totient is φ = 13221376.

The previous prime is 13228717. The next prime is 13228741. The reversal of 13228729 is 92782231.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 92782231 = 233 ⋅398207.

It is an interprime number because it is at equal distance from previous prime (13228717) and next prime (13228741).

It can be written as a sum of positive squares in 2 ways, for example, as 12766329 + 462400 = 3573^2 + 680^2 .

It is a cyclic number.

It is not a de Polignac number, because 13228729 - 2²¹ = 11131577 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13228694 and 13228703.

It is not an unprimeable number, because it can be changed into a prime (13228759) 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, 1029 + ... + 5245.

It is an arithmetic number, because the mean of its divisors is an integer number (3309021).

Almost surely, 2^13228729 is an apocalyptic number.

It is an amenable number.

13228729 is a deficient number, since it is larger than the sum of its proper divisors (7355).

13228729 is an equidigital number, since it uses as much as digits as its factorization.

13228729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7354.

The product of its digits is 12096, while the sum is 34.

The square root of 13228729 is about 3637.1319745096. The cubic root of 13228729 is about 236.5044807826.

The spelling of 13228729 in words is "thirteen million, two hundred twenty-eight thousand, seven hundred twenty-nine".