28724145 has 16 divisors (see below), whose sum is σ = 46827072. Its totient is φ = 15030080.

The previous prime is 28724117. The next prime is 28724147. The reversal of 28724145 is 54142782.

It is not a de Polignac number, because 28724145 - 2⁶ = 28724081 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28724147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17271 + ... + 18860.

It is an arithmetic number, because the mean of its divisors is an integer number (2926692).

Almost surely, 2^28724145 is an apocalyptic number.

It is an amenable number.

28724145 is a deficient number, since it is larger than the sum of its proper divisors (18102927).

28724145 is a wasteful number, since it uses less digits than its factorization.

28724145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36192.

The product of its digits is 17920, while the sum is 33.

The square root of 28724145 is about 5359.4911139025. The cubic root of 28724145 is about 306.2544233708.

The spelling of 28724145 in words is "twenty-eight million, seven hundred twenty-four thousand, one hundred forty-five".