640146340 has 12 divisors (see below), whose sum is σ = 1344307356. Its totient is φ = 256058528.

The previous prime is 640146323. The next prime is 640146343. The reversal of 640146340 is 43641046.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 493639524 + 146506816 = 22218^2 + 12104^2 .

It is a junction number, because it is equal to n+sod(n) for n = 640146299 and 640146308.

It is not an unprimeable number, because it can be changed into a prime (640146343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16003639 + ... + 16003678.

It is an arithmetic number, because the mean of its divisors is an integer number (112025613).

Almost surely, 2^640146340 is an apocalyptic number.

It is an amenable number.

640146340 is an abundant number, since it is smaller than the sum of its proper divisors (704161016).

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

640146340 is a wasteful number, since it uses less digits than its factorization.

640146340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32007326 (or 32007324 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 640146340 is about 25301.1134142354. The cubic root of 640146340 is about 861.8395543347.

Adding to 640146340 its reverse (43641046), we get a palindrome (683787386).

The spelling of 640146340 in words is "six hundred forty million, one hundred forty-six thousand, three hundred forty".