105728509 has 2 divisors, whose sum is σ = 105728510. Its totient is φ = 105728508.

The previous prime is 105728477. The next prime is 105728549. The reversal of 105728509 is 905827501.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78375609 + 27352900 = 8853^2 + 5230^2 .

It is an emirp because it is prime and its reverse (905827501) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 105728509 - 2⁵ = 105728477 is a prime.

It is a super-2 number, since 2×105728509² = 22357035230726162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (105728549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52864254 + 52864255.

It is an arithmetic number, because the mean of its divisors is an integer number (52864255).

Almost surely, 2^105728509 is an apocalyptic number.

It is an amenable number.

105728509 is a deficient number, since it is larger than the sum of its proper divisors (1).

105728509 is an equidigital number, since it uses as much as digits as its factorization.

105728509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 105728509 is about 10282.4369193300. The cubic root of 105728509 is about 472.8579581745.

The spelling of 105728509 in words is "one hundred five million, seven hundred twenty-eight thousand, five hundred nine".