645858189 has 12 divisors (see below), whose sum is σ = 933431772. Its totient is φ = 430329600.

The previous prime is 645858181. The next prime is 645858197. The reversal of 645858189 is 981858546.

It is a happy number.

645858189 is a `hidden beast` number, since 6 + 4 + 58 + 581 + 8 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (645858181) and next prime (645858197).

It can be written as a sum of positive squares in 2 ways, for example, as 45118089 + 600740100 = 6717^2 + 24510^2 .

It is not a de Polignac number, because 645858189 - 2³ = 645858181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645858181) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2532 + ... + 36029.

It is an arithmetic number, because the mean of its divisors is an integer number (77785981).

Almost surely, 2^645858189 is an apocalyptic number.

It is an amenable number.

645858189 is a deficient number, since it is larger than the sum of its proper divisors (287573583).

645858189 is a wasteful number, since it uses less digits than its factorization.

645858189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40428 (or 40425 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 54.

The square root of 645858189 is about 25413.7401615740. The cubic root of 645858189 is about 864.3952867504.

The spelling of 645858189 in words is "six hundred forty-five million, eight hundred fifty-eight thousand, one hundred eighty-nine".