85728661 has 2 divisors, whose sum is σ = 85728662. Its totient is φ = 85728660.

The previous prime is 85728653. The next prime is 85728673. The reversal of 85728661 is 16682758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84529636 + 1199025 = 9194^2 + 1095^2 .

It is a cyclic number.

It is not a de Polignac number, because 85728661 - 2³ = 85728653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85728641) 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, 42864330 + 42864331.

It is an arithmetic number, because the mean of its divisors is an integer number (42864331).

Almost surely, 2^85728661 is an apocalyptic number.

It is an amenable number.

85728661 is a deficient number, since it is larger than the sum of its proper divisors (1).

85728661 is an equidigital number, since it uses as much as digits as its factorization.

85728661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 161280, while the sum is 43.

The square root of 85728661 is about 9258.9773193372. The cubic root of 85728661 is about 440.9357855778.

The spelling of 85728661 in words is "eighty-five million, seven hundred twenty-eight thousand, six hundred sixty-one".