85665553 has 6 divisors (see below), whose sum is σ = 86066486. Its totient is φ = 85266432.

The previous prime is 85665551. The next prime is 85665557. The reversal of 85665553 is 35556658.

It can be written as a sum of positive squares in 3 ways, for example, as 83685904 + 1979649 = 9148^2 + 1407^2 .

It is not a de Polignac number, because 85665553 - 2¹ = 85665551 is a prime.

It is a super-3 number, since 3×85665553³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85665551) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 65401 + ... + 66697.

Almost surely, 2^85665553 is an apocalyptic number.

It is an amenable number.

85665553 is a deficient number, since it is larger than the sum of its proper divisors (400933).

85665553 is an equidigital number, since it uses as much as digits as its factorization.

85665553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1811 (or 1554 counting only the distinct ones).

The product of its digits is 540000, while the sum is 43.

The square root of 85665553 is about 9255.5687561597. The cubic root of 85665553 is about 440.8275627032.

The spelling of 85665553 in words is "eighty-five million, six hundred sixty-five thousand, five hundred fifty-three".