640343144 has 64 divisors (see below), whose sum is σ = 1393459200. Its totient is φ = 270212544.

The previous prime is 640343141. The next prime is 640343147. The reversal of 640343144 is 441343046.

It is an interprime number because it is at equal distance from previous prime (640343141) and next prime (640343147).

It is not an unprimeable number, because it can be changed into a prime (640343141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1272797 + ... + 1273299.

It is an arithmetic number, because the mean of its divisors is an integer number (21772800).

Almost surely, 2^640343144 is an apocalyptic number.

It is an amenable number.

640343144 is an abundant number, since it is smaller than the sum of its proper divisors (753116056).

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

640343144 is a wasteful number, since it uses less digits than its factorization.

640343144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822 (or 818 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 29.

The square root of 640343144 is about 25305.0023513139. The cubic root of 640343144 is about 861.9278654402.

The spelling of 640343144 in words is "six hundred forty million, three hundred forty-three thousand, one hundred forty-four".