645558085 has 12 divisors (see below), whose sum is σ = 822920868. Its totient is φ = 486066176.

The previous prime is 645558061. The next prime is 645558091. The reversal of 645558085 is 580855546.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 195524289 + 450033796 = 13983^2 + 21214^2 .

It is not a de Polignac number, because 645558085 - 2¹³ = 645549893 is a prime.

It is a super-2 number, since 2×645558085² = 833490482217734450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 221932 + ... + 224821.

It is an arithmetic number, because the mean of its divisors is an integer number (68576739).

Almost surely, 2^645558085 is an apocalyptic number.

It is an amenable number.

645558085 is a deficient number, since it is larger than the sum of its proper divisors (177362783).

645558085 is a wasteful number, since it uses less digits than its factorization.

645558085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446792 (or 446775 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 46.

The square root of 645558085 is about 25407.8351104536. The cubic root of 645558085 is about 864.2613829116.

The spelling of 645558085 in words is "six hundred forty-five million, five hundred fifty-eight thousand, eighty-five".