643045877865 has 32 divisors (see below), whose sum is σ = 1180069862400. Its totient is φ = 331894644480.

The previous prime is 643045877861. The next prime is 643045877893. The reversal of 643045877865 is 568778540346.

643045877865 is a `hidden beast` number, since 6 + 4 + 30 + 458 + 77 + 86 + 5 = 666.

It is not a de Polignac number, because 643045877865 - 2² = 643045877861 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (643045877861) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 76823280 + ... + 76831649.

It is an arithmetic number, because the mean of its divisors is an integer number (36877183200).

Almost surely, 2^643045877865 is an apocalyptic number.

It is an amenable number.

643045877865 is a deficient number, since it is larger than the sum of its proper divisors (537023984535).

643045877865 is a wasteful number, since it uses less digits than its factorization.

643045877865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153654974 (or 153654968 counting only the distinct ones).

The product of its (nonzero) digits is 135475200, while the sum is 63.

The spelling of 643045877865 in words is "six hundred forty-three billion, forty-five million, eight hundred seventy-seven thousand, eight hundred sixty-five".