645472872 has 48 divisors (see below), whose sum is σ = 1907081280. Its totient is φ = 195597600.

The previous prime is 645472859. The next prime is 645472873. The reversal of 645472872 is 278274546.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (645472873) 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 11 ways as a sum of consecutive naturals, for example, 406704 + ... + 408287.

It is an arithmetic number, because the mean of its divisors is an integer number (39730860).

Almost surely, 2^645472872 is an apocalyptic number.

It is an amenable number.

645472872 is an abundant number, since it is smaller than the sum of its proper divisors (1261608408).

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

645472872 is a wasteful number, since it uses less digits than its factorization.

645472872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 815014 (or 815007 counting only the distinct ones).

The product of its digits is 752640, while the sum is 45.

The square root of 645472872 is about 25406.1581511255. The cubic root of 645472872 is about 864.2233540352.

The spelling of 645472872 in words is "six hundred forty-five million, four hundred seventy-two thousand, eight hundred seventy-two".