643243044255 has 32 divisors (see below), whose sum is σ = 1176411846144. Its totient is φ = 294004964736.

The previous prime is 643243044229. The next prime is 643243044307. The reversal of 643243044255 is 552440342346.

It is a happy number.

It is not a de Polignac number, because 643243044255 - 2⁹ = 643243043743 is a prime.

It is a super-2 number, since 2×643243044255² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 126504 + ... + 1141266.

It is an arithmetic number, because the mean of its divisors is an integer number (36762870192).

Almost surely, 2^643243044255 is an apocalyptic number.

643243044255 is a deficient number, since it is larger than the sum of its proper divisors (533168801889).

643243044255 is a wasteful number, since it uses less digits than its factorization.

643243044255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020815.

The product of its (nonzero) digits is 1382400, while the sum is 42.

The spelling of 643243044255 in words is "six hundred forty-three billion, two hundred forty-three million, forty-four thousand, two hundred fifty-five".