645554960 has 40 divisors (see below), whose sum is σ = 1511896536. Its totient is φ = 256332800.

The previous prime is 645554941. The next prime is 645554971. The reversal of 645554960 is 69455546.

It can be written as a sum of positive squares in 4 ways, for example, as 4857616 + 640697344 = 2204^2 + 25312^2 .

It is a tau number, because it is divible by the number of its divisors (40).

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 7 ways as a sum of consecutive naturals, for example, 18491 + ... + 40410.

Almost surely, 2^645554960 is an apocalyptic number.

It is an amenable number.

645554960 is an abundant number, since it is smaller than the sum of its proper divisors (866341576).

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

645554960 is a wasteful number, since it uses less digits than its factorization.

645554960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59051 (or 59045 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 44.

The square root of 645554960 is about 25407.7736136010. The cubic root of 645554960 is about 864.2599883451.

The spelling of 645554960 in words is "six hundred forty-five million, five hundred fifty-four thousand, nine hundred sixty".