640511452 has 24 divisors (see below), whose sum is σ = 1336720896. Its totient is φ = 262569648.

The previous prime is 640511449. The next prime is 640511453. The reversal of 640511452 is 254115046.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 640511452.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640511453) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 496648 + ... + 497935.

It is an arithmetic number, because the mean of its divisors is an integer number (55696704).

Almost surely, 2^640511452 is an apocalyptic number.

It is an amenable number.

640511452 is an abundant number, since it is smaller than the sum of its proper divisors (696209444).

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

640511452 is a wasteful number, since it uses less digits than its factorization.

640511452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 994617 (or 994615 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 28.

The square root of 640511452 is about 25308.3277203374. The cubic root of 640511452 is about 862.0033752916.

Adding to 640511452 its reverse (254115046), we get a palindrome (894626498).

The spelling of 640511452 in words is "six hundred forty million, five hundred eleven thousand, four hundred fifty-two".