645287020 has 48 divisors (see below), whose sum is σ = 1639794240. Its totient is φ = 208226304.

The previous prime is 645287009. The next prime is 645287023. The reversal of 645287020 is 20782546.

645287020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (645287023) 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, 133185 + ... + 137944.

It is an arithmetic number, because the mean of its divisors is an integer number (34162380).

Almost surely, 2^645287020 is an apocalyptic number.

It is an amenable number.

645287020 is an abundant number, since it is smaller than the sum of its proper divisors (994507220).

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

645287020 is a wasteful number, since it uses less digits than its factorization.

645287020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271162 (or 271160 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 34.

The square root of 645287020 is about 25402.5002706427. The cubic root of 645287020 is about 864.1404003518.

The spelling of 645287020 in words is "six hundred forty-five million, two hundred eighty-seven thousand, twenty".