643622240 has 48 divisors (see below), whose sum is σ = 1522825920. Its totient is φ = 257064960.

The previous prime is 643622137. The next prime is 643622251. The reversal of 643622240 is 42226346.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120425 + ... + 125655.

It is an arithmetic number, because the mean of its divisors is an integer number (31725540).

Almost surely, 2^643622240 is an apocalyptic number.

It is an amenable number.

643622240 is an abundant number, since it is smaller than the sum of its proper divisors (879203680).

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

643622240 is a wasteful number, since it uses less digits than its factorization.

643622240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6015 (or 6007 counting only the distinct ones).

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

The square root of 643622240 is about 25369.7110744289. The cubic root of 643622240 is about 863.3966266297.

Adding to 643622240 its reverse (42226346), we get a palindrome (685848586).

The spelling of 643622240 in words is "six hundred forty-three million, six hundred twenty-two thousand, two hundred forty".