645775101 has 12 divisors (see below), whose sum is σ = 934346140. Its totient is φ = 429796800.

The previous prime is 645775087. The next prime is 645775121. The reversal of 645775101 is 101577546.

645775101 is a `hidden beast` number, since 645 + 7 + 7 + 5 + 1 + 0 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 422302500 + 223472601 = 20550^2 + 14949^2 .

It is not a de Polignac number, because 645775101 - 2⁹ = 645774589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645775121) 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, 54286 + ... + 65103.

Almost surely, 2^645775101 is an apocalyptic number.

It is an amenable number.

645775101 is a deficient number, since it is larger than the sum of its proper divisors (288571039).

645775101 is a wasteful number, since it uses less digits than its factorization.

645775101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119996 (or 119993 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 36.

The square root of 645775101 is about 25412.1054027406. The cubic root of 645775101 is about 864.3582177483.

The spelling of 645775101 in words is "six hundred forty-five million, seven hundred seventy-five thousand, one hundred one".