645001520 has 40 divisors (see below), whose sum is σ = 1527933456. Its totient is φ = 253131008.

The previous prime is 645001519. The next prime is 645001523. The reversal of 645001520 is 25100546.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (645001523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71822 + ... + 80301.

Almost surely, 2^645001520 is an apocalyptic number.

It is an amenable number.

645001520 is an abundant number, since it is smaller than the sum of its proper divisors (882931936).

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

645001520 is a wasteful number, since it uses less digits than its factorization.

645001520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152189 (or 152183 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 645001520 is about 25396.8801233537. The cubic root of 645001520 is about 864.0129384779.

The spelling of 645001520 in words is "six hundred forty-five million, one thousand, five hundred twenty".