643552503 has 16 divisors (see below), whose sum is σ = 946598400. Its totient is φ = 385647680.

The previous prime is 643552457. The next prime is 643552519. The reversal of 643552503 is 305255346.

It is not a de Polignac number, because 643552503 - 2¹⁰ = 643551479 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643552573) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 106623 + ... + 112496.

It is an arithmetic number, because the mean of its divisors is an integer number (59162400).

Almost surely, 2^643552503 is an apocalyptic number.

643552503 is a deficient number, since it is larger than the sum of its proper divisors (303045897).

643552503 is a wasteful number, since it uses less digits than its factorization.

643552503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219222.

The product of its (nonzero) digits is 54000, while the sum is 33.

The square root of 643552503 is about 25368.3366226483. The cubic root of 643552503 is about 863.3654422581.

The spelling of 643552503 in words is "six hundred forty-three million, five hundred fifty-two thousand, five hundred three".