643523019865 has 48 divisors (see below), whose sum is σ = 851697177408. Its totient is φ = 466429040000.

The previous prime is 643523019787. The next prime is 643523019871. The reversal of 643523019865 is 568910325346.

It is not a de Polignac number, because 643523019865 - 2³³ = 634933085273 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 431026059 + ... + 431027551.

It is an arithmetic number, because the mean of its divisors is an integer number (17743691196).

Almost surely, 2^643523019865 is an apocalyptic number.

It is an amenable number.

643523019865 is a deficient number, since it is larger than the sum of its proper divisors (208174157543).

643523019865 is a wasteful number, since it uses less digits than its factorization.

643523019865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3462 (or 3451 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 52.

The spelling of 643523019865 in words is "six hundred forty-three billion, five hundred twenty-three million, nineteen thousand, eight hundred sixty-five".