643777057 has 16 divisors (see below), whose sum is σ = 844876800. Its totient is φ = 475241040.

The previous prime is 643777051. The next prime is 643777067. The reversal of 643777057 is 750777346.

It is a cyclic number.

It is not a de Polignac number, because 643777057 - 2³ = 643777049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643776998 and 643777016.

It is not an unprimeable number, because it can be changed into a prime (643777051) 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 in 15 ways as a sum of consecutive naturals, for example, 218557 + ... + 221482.

It is an arithmetic number, because the mean of its divisors is an integer number (52804800).

Almost surely, 2^643777057 is an apocalyptic number.

It is an amenable number.

643777057 is a deficient number, since it is larger than the sum of its proper divisors (201099743).

643777057 is a wasteful number, since it uses less digits than its factorization.

643777057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440076.

The product of its (nonzero) digits is 864360, while the sum is 46.

The square root of 643777057 is about 25372.7621082136. The cubic root of 643777057 is about 863.4658482689.

The spelling of 643777057 in words is "six hundred forty-three million, seven hundred seventy-seven thousand, fifty-seven".