645084 has 60 divisors (see below), whose sum is σ = 1849848. Its totient is φ = 194400.

The previous prime is 645083. The next prime is 645091. The reversal of 645084 is 480546.

It is a super-2 number, since 2×645084² = 832266734112, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645083) 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 19 ways as a sum of consecutive naturals, for example, 3474 + ... + 3654.

2⁶⁴⁵⁰⁸⁴ 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 645084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (924924).

645084 is an abundant number, since it is smaller than the sum of its proper divisors (1204764).

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

645084 is a wasteful number, since it uses less digits than its factorization.

645084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 645084 is about 803.1712146236. The cubic root of 645084 is about 86.4049765652.

The spelling of 645084 in words is "six hundred forty-five thousand, eighty-four".