645520610 has 48 divisors (see below), whose sum is σ = 1355366520. Its totient is φ = 220711680.

The previous prime is 645520591. The next prime is 645520627. The reversal of 645520610 is 16025546.

It can be written as a sum of positive squares in 4 ways, for example, as 641760889 + 3759721 = 25333^2 + 1939^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 198800 + ... + 202020.

Almost surely, 2^645520610 is an apocalyptic number.

645520610 is an abundant number, since it is smaller than the sum of its proper divisors (709845910).

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

645520610 is a wasteful number, since it uses less digits than its factorization.

645520610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3651 (or 3644 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 645520610 is about 25407.0976303867. The cubic root of 645520610 is about 864.2446589727.

The spelling of 645520610 in words is "six hundred forty-five million, five hundred twenty thousand, six hundred ten".