643531610225556 has 48 divisors (see below), whose sum is σ = 1796754923140800. Its totient is φ = 198009726222816.

The previous prime is 643531610225437. The next prime is 643531610225557. The reversal of 643531610225556 is 655522016135346.

643531610225556 is a `hidden beast` number, since 6 + 4 + 3 + 5 + 3 + 1 + 61 + 0 + 2 + 25 + 556 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643531610225557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 229177922466 + ... + 229177925273.

It is an arithmetic number, because the mean of its divisors is an integer number (37432394232100).

Almost surely, 2^{643531610225556} is an apocalyptic number.

It is an amenable number.

643531610225556 is an abundant number, since it is smaller than the sum of its proper divisors (1153223312915244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643531610225556 is a wasteful number, since it uses less digits than its factorization.

643531610225556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 458355847765 (or 458355847757 counting only the distinct ones).

The product of its (nonzero) digits is 19440000, while the sum is 54.

The spelling of 643531610225556 in words is "six hundred forty-three trillion, five hundred thirty-one billion, six hundred ten million, two hundred twenty-five thousand, five hundred fifty-six".