640143544 has 32 divisors (see below), whose sum is σ = 1253946240. Its totient is φ = 305791200.

The previous prime is 640143533. The next prime is 640143547. The reversal of 640143544 is 445341046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640143547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 213979 + ... + 216949.

It is an arithmetic number, because the mean of its divisors is an integer number (39185820).

Almost surely, 2^640143544 is an apocalyptic number.

It is an amenable number.

640143544 is a deficient number, since it is larger than the sum of its proper divisors (613802696).

640143544 is a wasteful number, since it uses less digits than its factorization.

640143544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4171 (or 4167 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 31.

The square root of 640143544 is about 25301.0581596897. The cubic root of 640143544 is about 861.8382995659.

The spelling of 640143544 in words is "six hundred forty million, one hundred forty-three thousand, five hundred forty-four".