643476536 has 8 divisors (see below), whose sum is σ = 1206518520. Its totient is φ = 321738264.

The previous prime is 643476529. The next prime is 643476557. The reversal of 643476536 is 635674346.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40217276 + ... + 40217291.

It is an arithmetic number, because the mean of its divisors is an integer number (150814815).

Almost surely, 2^643476536 is an apocalyptic number.

It is an amenable number.

643476536 is a deficient number, since it is larger than the sum of its proper divisors (563041984).

643476536 is a wasteful number, since it uses less digits than its factorization.

643476536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80434573 (or 80434569 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 44.

The square root of 643476536 is about 25366.8392985803. The cubic root of 643476536 is about 863.3314694467.

The spelling of 643476536 in words is "six hundred forty-three million, four hundred seventy-six thousand, five hundred thirty-six".