645813567 has 24 divisors (see below), whose sum is σ = 1105593216. Its totient is φ = 369035352.

The previous prime is 645813559. The next prime is 645813583. The reversal of 645813567 is 765318546.

645813567 is a `hidden beast` number, since 6 + 4 + 5 + 81 + 3 + 567 = 666.

It is not a de Polignac number, because 645813567 - 2³ = 645813559 is a prime.

It is a super-3 number, since 3×645813567³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645813767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 188133 + ... + 191534.

It is an arithmetic number, because the mean of its divisors is an integer number (46066384).

Almost surely, 2^645813567 is an apocalyptic number.

645813567 is a deficient number, since it is larger than the sum of its proper divisors (459779649).

645813567 is an equidigital number, since it uses as much as digits as its factorization.

645813567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379689 (or 379677 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 645813567 is about 25412.8622354901. The cubic root of 645813567 is about 864.3753794212.

The spelling of 645813567 in words is "six hundred forty-five million, eight hundred thirteen thousand, five hundred sixty-seven".