643572976 has 10 divisors (see below), whose sum is σ = 1246922672. Its totient is φ = 321786480.

The previous prime is 643572971. The next prime is 643572977. The reversal of 643572976 is 679275346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643572971) by changing a digit.

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 as a sum of consecutive naturals, namely, 20111640 + ... + 20111671.

Almost surely, 2^643572976 is an apocalyptic number.

It is an amenable number.

643572976 is a deficient number, since it is larger than the sum of its proper divisors (603349696).

643572976 is a wasteful number, since it uses less digits than its factorization.

643572976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40223319 (or 40223313 counting only the distinct ones).

The product of its digits is 1905120, while the sum is 49.

The square root of 643572976 is about 25368.7401342676. The cubic root of 643572976 is about 863.3745974258.

The spelling of 643572976 in words is "six hundred forty-three million, five hundred seventy-two thousand, nine hundred seventy-six".