645506500 has 48 divisors (see below), whose sum is σ = 1471107456. Its totient is φ = 246972000.

The previous prime is 645506479. The next prime is 645506503. The reversal of 645506500 is 5605546.

645506500 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (645506503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16566 + ... + 39565.

It is an arithmetic number, because the mean of its divisors is an integer number (30648072).

Almost surely, 2^645506500 is an apocalyptic number.

It is an amenable number.

645506500 is an abundant number, since it is smaller than the sum of its proper divisors (825600956).

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

645506500 is a wasteful number, since it uses less digits than its factorization.

645506500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56173 (or 56161 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 31.

The square root of 645506500 is about 25406.8199505566. The cubic root of 645506500 is about 864.2383619463.

The spelling of 645506500 in words is "six hundred forty-five million, five hundred six thousand, five hundred".