28724345 has 8 divisors (see below), whose sum is σ = 37120776. Its totient is φ = 21211776.

The previous prime is 28724341. The next prime is 28724347. The reversal of 28724345 is 54342782.

It can be written as a sum of positive squares in 4 ways, for example, as 26896 + 28697449 = 164^2 + 5357^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28724345 - 2² = 28724341 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28724341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 220892 + ... + 221021.

It is an arithmetic number, because the mean of its divisors is an integer number (4640097).

Almost surely, 2^28724345 is an apocalyptic number.

It is an amenable number.

28724345 is a deficient number, since it is larger than the sum of its proper divisors (8396431).

28724345 is a wasteful number, since it uses less digits than its factorization.

28724345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441931.

The product of its digits is 53760, while the sum is 35.

The square root of 28724345 is about 5359.5097723579. The cubic root of 28724345 is about 306.2551341635.

The spelling of 28724345 in words is "twenty-eight million, seven hundred twenty-four thousand, three hundred forty-five".