640512 has 60 divisors (see below), whose sum is σ = 1861860. Its totient is φ = 211968.

The previous prime is 640499. The next prime is 640529. The reversal of 640512 is 215046.

It is a happy number.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640512.

It is an unprimeable number.

640512 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4539 + ... + 4677.

It is an arithmetic number, because the mean of its divisors is an integer number (31031).

2⁶⁴⁰⁵¹² 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 640512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (930930).

640512 is an abundant number, since it is smaller than the sum of its proper divisors (1221348).

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

640512 is a wasteful number, since it uses less digits than its factorization.

640512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 144 counting only the distinct ones).

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

The square root of 640512 is about 800.3199360256. The cubic root of 640512 is about 86.2003621125.

Adding to 640512 its reverse (215046), we get a palindrome (855558).

The spelling of 640512 in words is "six hundred forty thousand, five hundred twelve".