639943530 has 16 divisors (see below), whose sum is σ = 1535864544. Its totient is φ = 170651600.

The previous prime is 639943517. The next prime is 639943531. The reversal of 639943530 is 35349936.

It is not an unprimeable number, because it can be changed into a prime (639943531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10665696 + ... + 10665755.

It is an arithmetic number, because the mean of its divisors is an integer number (95991534).

Almost surely, 2^639943530 is an apocalyptic number.

639943530 is an abundant number, since it is smaller than the sum of its proper divisors (895921014).

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

639943530 is a wasteful number, since it uses less digits than its factorization.

639943530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21331461.

The product of its (nonzero) digits is 262440, while the sum is 42.

The square root of 639943530 is about 25297.1051703550. The cubic root of 639943530 is about 861.7485292408.

The spelling of 639943530 in words is "six hundred thirty-nine million, nine hundred forty-three thousand, five hundred thirty".