643878902 has 16 divisors (see below), whose sum is σ = 978318432. Its totient is φ = 317799360.

The previous prime is 643878901. The next prime is 643878913. The reversal of 643878902 is 209878346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643878901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43103 + ... + 56085.

It is an arithmetic number, because the mean of its divisors is an integer number (61144902).

Almost surely, 2^643878902 is an apocalyptic number.

643878902 is a deficient number, since it is larger than the sum of its proper divisors (334439530).

643878902 is a wasteful number, since it uses less digits than its factorization.

643878902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13303.

The product of its (nonzero) digits is 580608, while the sum is 47.

The square root of 643878902 is about 25374.7690038747. The cubic root of 643878902 is about 863.5113790632.

The spelling of 643878902 in words is "six hundred forty-three million, eight hundred seventy-eight thousand, nine hundred two".