28172513 has 2 divisors, whose sum is σ = 28172514. Its totient is φ = 28172512.

The previous prime is 28172479. The next prime is 28172549. The reversal of 28172513 is 31527182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27699169 + 473344 = 5263^2 + 688^2 .

It is a cyclic number.

It is not a de Polignac number, because 28172513 - 2⁶ = 28172449 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (28172563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14086256 + 14086257.

It is an arithmetic number, because the mean of its divisors is an integer number (14086257).

Almost surely, 2^28172513 is an apocalyptic number.

It is an amenable number.

28172513 is a deficient number, since it is larger than the sum of its proper divisors (1).

28172513 is an equidigital number, since it uses as much as digits as its factorization.

28172513 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 29.

The square root of 28172513 is about 5307.7785372037. The cubic root of 28172513 is about 304.2812530138.

Adding to 28172513 its reverse (31527182), we get a palindrome (59699695).

The spelling of 28172513 in words is "twenty-eight million, one hundred seventy-two thousand, five hundred thirteen".