28752121 has 2 divisors, whose sum is σ = 28752122. Its totient is φ = 28752120.

The previous prime is 28752103. The next prime is 28752127. The reversal of 28752121 is 12125782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15327225 + 13424896 = 3915^2 + 3664^2 .

It is a cyclic number.

It is not a de Polignac number, because 28752121 - 2⁹ = 28751609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28752121.

It is not a weakly prime, because it can be changed into another prime (28752127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14376060 + 14376061.

It is an arithmetic number, because the mean of its divisors is an integer number (14376061).

Almost surely, 2^28752121 is an apocalyptic number.

It is an amenable number.

28752121 is a deficient number, since it is larger than the sum of its proper divisors (1).

28752121 is an equidigital number, since it uses as much as digits as its factorization.

28752121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2240, while the sum is 28.

The square root of 28752121 is about 5362.1004280039. The cubic root of 28752121 is about 306.3538170309.

The spelling of 28752121 in words is "twenty-eight million, seven hundred fifty-two thousand, one hundred twenty-one".