643630240 has 48 divisors (see below), whose sum is σ = 1658815200. Its totient is φ = 234046720.

The previous prime is 643630237. The next prime is 643630243. The reversal of 643630240 is 42036346.

It is an interprime number because it is at equal distance from previous prime (643630237) and next prime (643630243).

It is a junction number, because it is equal to n+sod(n) for n = 643630199 and 643630208.

It is not an unprimeable number, because it can be changed into a prime (643630243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 181090 + ... + 184609.

It is an arithmetic number, because the mean of its divisors is an integer number (34558650).

Almost surely, 2^643630240 is an apocalyptic number.

It is an amenable number.

643630240 is an abundant number, since it is smaller than the sum of its proper divisors (1015184960).

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

643630240 is a wasteful number, since it uses less digits than its factorization.

643630240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365725 (or 365717 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 28.

The square root of 643630240 is about 25369.8687422698. The cubic root of 643630240 is about 863.4002038545.

Adding to 643630240 its reverse (42036346), we get a palindrome (685666586).

The spelling of 643630240 in words is "six hundred forty-three million, six hundred thirty thousand, two hundred forty".