643623456 has 48 divisors (see below), whose sum is σ = 1930872384. Its totient is φ = 183892224.

The previous prime is 643623443. The next prime is 643623469. The reversal of 643623456 is 654326346.

It is an interprime number because it is at equal distance from previous prime (643623443) and next prime (643623469).

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×643623456² = 828502306226767872, which contains 22 as substring.

It is an unprimeable number.

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, 478215 + ... + 479558.

It is an arithmetic number, because the mean of its divisors is an integer number (40226508).

Almost surely, 2^643623456 is an apocalyptic number.

It is an amenable number.

643623456 is an abundant number, since it is smaller than the sum of its proper divisors (1287248928).

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

643623456 is a wasteful number, since it uses less digits than its factorization.

643623456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957793 (or 957785 counting only the distinct ones).

The product of its digits is 311040, while the sum is 39.

The square root of 643623456 is about 25369.7350400039. The cubic root of 643623456 is about 863.3971703698.

It can be divided in two parts, 6436 and 23456, that added together give a palindrome (29892).

The spelling of 643623456 in words is "six hundred forty-three million, six hundred twenty-three thousand, four hundred fifty-six".