28931545 has 4 divisors (see below), whose sum is σ = 34717860. Its totient is φ = 23145232.

The previous prime is 28931537. The next prime is 28931549. The reversal of 28931545 is 54513982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54513982 = 2 ⋅27256991.

It can be written as a sum of positive squares in 2 ways, for example, as 16744464 + 12187081 = 4092^2 + 3491^2 .

It is a cyclic number.

It is not a de Polignac number, because 28931545 - 2³ = 28931537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28931549) 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, 2893150 + ... + 2893159.

It is an arithmetic number, because the mean of its divisors is an integer number (8679465).

Almost surely, 2^28931545 is an apocalyptic number.

It is an amenable number.

28931545 is a deficient number, since it is larger than the sum of its proper divisors (5786315).

28931545 is an equidigital number, since it uses as much as digits as its factorization.

28931545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5786314.

The product of its digits is 43200, while the sum is 37.

The square root of 28931545 is about 5378.8051647183. The cubic root of 28931545 is about 306.9897502122.

The spelling of 28931545 in words is "twenty-eight million, nine hundred thirty-one thousand, five hundred forty-five".