645127856 has 40 divisors (see below), whose sum is σ = 1325165184. Its totient is φ = 303713280.

The previous prime is 645127841. The next prime is 645127877. The reversal of 645127856 is 658721546.

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 7 ways as a sum of consecutive naturals, for example, 776 + ... + 35928.

Almost surely, 2^645127856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645127856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (662582592).

645127856 is an abundant number, since it is smaller than the sum of its proper divisors (680037328).

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

645127856 is a wasteful number, since it uses less digits than its factorization.

645127856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35229 (or 35223 counting only the distinct ones).

The product of its digits is 403200, while the sum is 44.

The square root of 645127856 is about 25399.3672362128. The cubic root of 645127856 is about 864.0693460001.

The spelling of 645127856 in words is "six hundred forty-five million, one hundred twenty-seven thousand, eight hundred fifty-six".