28185907 has 2 divisors, whose sum is σ = 28185908. Its totient is φ = 28185906.

The previous prime is 28185841. The next prime is 28185917. The reversal of 28185907 is 70958182.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28185907 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28185907.

It is not a weakly prime, because it can be changed into another prime (28185917) 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, 14092953 + 14092954.

It is an arithmetic number, because the mean of its divisors is an integer number (14092954).

Almost surely, 2^28185907 is an apocalyptic number.

28185907 is a deficient number, since it is larger than the sum of its proper divisors (1).

28185907 is an equidigital number, since it uses as much as digits as its factorization.

28185907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 28185907 is about 5309.0401203984. The cubic root of 28185907 is about 304.3294666444.

It can be divided in two parts, 28185 and 907, that added together give a palindrome (29092).

The spelling of 28185907 in words is "twenty-eight million, one hundred eighty-five thousand, nine hundred seven".