643808902 has 16 divisors (see below), whose sum is σ = 1056700224. Its totient is φ = 291753000.

The previous prime is 643808849. The next prime is 643808909. The reversal of 643808902 is 209808346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643808909) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36924 + ... + 51487.

It is an arithmetic number, because the mean of its divisors is an integer number (66043764).

Almost surely, 2^643808902 is an apocalyptic number.

643808902 is a deficient number, since it is larger than the sum of its proper divisors (412891322).

643808902 is a wasteful number, since it uses less digits than its factorization.

643808902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88755.

The product of its (nonzero) digits is 82944, while the sum is 40.

The square root of 643808902 is about 25373.3896434828. The cubic root of 643808902 is about 863.4800854007.

The spelling of 643808902 in words is "six hundred forty-three million, eight hundred eight thousand, nine hundred two".