645440324 has 12 divisors (see below), whose sum is σ = 1133377644. Its totient is φ = 321618144.

The previous prime is 645440311. The next prime is 645440347. The reversal of 645440324 is 423044546.

It can be written as a sum of positive squares in 2 ways, for example, as 306880324 + 338560000 = 17518^2 + 18400^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 274187 + ... + 276530.

It is an arithmetic number, because the mean of its divisors is an integer number (94448137).

Almost surely, 2^645440324 is an apocalyptic number.

It is an amenable number.

645440324 is a deficient number, since it is larger than the sum of its proper divisors (487937320).

645440324 is a wasteful number, since it uses less digits than its factorization.

645440324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551014 (or 551012 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 32.

The square root of 645440324 is about 25405.5175896891. The cubic root of 645440324 is about 864.2088276233.

The spelling of 645440324 in words is "six hundred forty-five million, four hundred forty thousand, three hundred twenty-four".