643256365503 has 8 divisors (see below), whose sum is σ = 875923561728. Its totient is φ = 419713373144.

The previous prime is 643256365487. The next prime is 643256365537. The reversal of 643256365503 is 305563652346.

It is a happy number.

643256365503 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643256365503 - 2⁴ = 643256365487 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643256365303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2281050801 + ... + 2281051082.

It is an arithmetic number, because the mean of its divisors is an integer number (109490445216).

Almost surely, 2^643256365503 is an apocalyptic number.

643256365503 is a deficient number, since it is larger than the sum of its proper divisors (232667196225).

643256365503 is a wasteful number, since it uses less digits than its factorization.

643256365503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4562101933.

The product of its (nonzero) digits is 5832000, while the sum is 48.

The spelling of 643256365503 in words is "six hundred forty-three billion, two hundred fifty-six million, three hundred sixty-five thousand, five hundred three".