645451040 has 48 divisors (see below), whose sum is σ = 1642181688. Its totient is φ = 238319616.

The previous prime is 645451039. The next prime is 645451049. The reversal of 645451040 is 40154546.

It can be written as a sum of positive squares in 4 ways, for example, as 595945744 + 49505296 = 24412^2 + 7036^2 .

It is a junction number, because it is equal to n+sod(n) for n = 645450994 and 645451012.

It is not an unprimeable number, because it can be changed into a prime (645451049) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 153077 + ... + 157236.

Almost surely, 2^645451040 is an apocalyptic number.

It is an amenable number.

645451040 is an abundant number, since it is smaller than the sum of its proper divisors (996730648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

645451040 is a wasteful number, since it uses less digits than its factorization.

645451040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310341 (or 310333 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 645451040 is about 25405.7284878824. The cubic root of 645451040 is about 864.2136103069.

The spelling of 645451040 in words is "six hundred forty-five million, four hundred fifty-one thousand, forty".