645012 has 72 divisors (see below), whose sum is σ = 1834560. Its totient is φ = 190080.

The previous prime is 645011. The next prime is 645013. The reversal of 645012 is 210546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (645011) and next prime (645013).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15712 + ... + 15752.

It is an arithmetic number, because the mean of its divisors is an integer number (25480).

2⁶⁴⁵⁰¹² 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 645012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (917280).

645012 is an abundant number, since it is smaller than the sum of its proper divisors (1189548).

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

645012 is a wasteful number, since it uses less digits than its factorization.

645012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 645012 is about 803.1263910494. The cubic root of 645012 is about 86.4017617954.

Adding to 645012 its reverse (210546), we get a palindrome (855558).

It can be divided in two parts, 6 and 45012, that multiplied together give a palindrome (270072).

The spelling of 645012 in words is "six hundred forty-five thousand, twelve".