643257848 has 8 divisors (see below), whose sum is σ = 1206108480. Its totient is φ = 321628920.

The previous prime is 643257847. The next prime is 643257851. The reversal of 643257848 is 848752346.

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

It is a super-2 number, since 2×643257848² = 827561318027182208, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643257847) 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 as a sum of consecutive naturals, namely, 40203608 + ... + 40203623.

It is an arithmetic number, because the mean of its divisors is an integer number (150763560).

Almost surely, 2^643257848 is an apocalyptic number.

It is an amenable number.

643257848 is a deficient number, since it is larger than the sum of its proper divisors (562850632).

643257848 is a wasteful number, since it uses less digits than its factorization.

643257848 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80407237 (or 80407233 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 47.

The square root of 643257848 is about 25362.5284228525. The cubic root of 643257848 is about 863.2336561807.

The spelling of 643257848 in words is "six hundred forty-three million, two hundred fifty-seven thousand, eight hundred forty-eight".