645443613 has 16 divisors (see below), whose sum is σ = 957123840. Its totient is φ = 429885792.

The previous prime is 645443597. The next prime is 645443627. The reversal of 645443613 is 316344546.

645443613 is a `hidden beast` number, since 645 + 4 + 4 + 3 + 6 + 1 + 3 = 666.

It is not a de Polignac number, because 645443613 - 2⁴ = 645443597 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645443693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18945 + ... + 40617.

It is an arithmetic number, because the mean of its divisors is an integer number (59820240).

Almost surely, 2^645443613 is an apocalyptic number.

It is an amenable number.

645443613 is a deficient number, since it is larger than the sum of its proper divisors (311680227).

645443613 is a wasteful number, since it uses less digits than its factorization.

645443613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22785 (or 22779 counting only the distinct ones).

The product of its digits is 103680, while the sum is 36.

The square root of 645443613 is about 25405.5823196399. The cubic root of 645443613 is about 864.2102955504.

The spelling of 645443613 in words is "six hundred forty-five million, four hundred forty-three thousand, six hundred thirteen".