645365878 has 16 divisors (see below), whose sum is σ = 1021494240. Its totient is φ = 305183296.

The previous prime is 645365869. The next prime is 645365879. The reversal of 645365878 is 878563546.

645365878 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×645365878³ (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 (645365879) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74725 + ... + 82912.

It is an arithmetic number, because the mean of its divisors is an integer number (63843390).

Almost surely, 2^645365878 is an apocalyptic number.

645365878 is a deficient number, since it is larger than the sum of its proper divisors (376128362).

645365878 is a wasteful number, since it uses less digits than its factorization.

645365878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157751.

The product of its digits is 4838400, while the sum is 52.

The square root of 645365878 is about 25404.0523932699. The cubic root of 645365878 is about 864.1755999895.

The spelling of 645365878 in words is "six hundred forty-five million, three hundred sixty-five thousand, eight hundred seventy-eight".