645134520 has 64 divisors (see below), whose sum is σ = 1937538720. Its totient is φ = 171846144.

The previous prime is 645134453. The next prime is 645134533. The reversal of 645134520 is 25431546.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 131634 + ... + 136446.

Almost surely, 2^645134520 is an apocalyptic number.

645134520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645134520 is an abundant number, since it is smaller than the sum of its proper divisors (1292404200).

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

645134520 is a wasteful number, since it uses less digits than its factorization.

645134520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5944 (or 5940 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 645134520 is about 25399.4984202444. The cubic root of 645134520 is about 864.0723211924.

The spelling of 645134520 in words is "six hundred forty-five million, one hundred thirty-four thousand, five hundred twenty".