28613729 has 4 divisors (see below), whose sum is σ = 28628484. Its totient is φ = 28598976.

The previous prime is 28613719. The next prime is 28613731. The reversal of 28613729 is 92731682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92731682 = 2 ⋅46365841.

It can be written as a sum of positive squares in 2 ways, for example, as 18835600 + 9778129 = 4340^2 + 3127^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28613729 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28613692 and 28613701.

It is not an unprimeable number, because it can be changed into a prime (28613719) 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, 3932 + ... + 8525.

It is an arithmetic number, because the mean of its divisors is an integer number (7157121).

Almost surely, 2^28613729 is an apocalyptic number.

It is an amenable number.

28613729 is a deficient number, since it is larger than the sum of its proper divisors (14755).

28613729 is a wasteful number, since it uses less digits than its factorization.

28613729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14754.

The product of its digits is 36288, while the sum is 38.

The square root of 28613729 is about 5349.1802175661. The cubic root of 28613729 is about 305.8615041024.

The spelling of 28613729 in words is "twenty-eight million, six hundred thirteen thousand, seven hundred twenty-nine".