643551013 has 16 divisors (see below), whose sum is σ = 748424320. Its totient is φ = 541956096.

The previous prime is 643551011. The next prime is 643551023. The reversal of 643551013 is 310155346.

It is a cyclic number.

It is not a de Polignac number, because 643551013 - 2¹ = 643551011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643551011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 201493 + ... + 204661.

It is an arithmetic number, because the mean of its divisors is an integer number (46776520).

Almost surely, 2^643551013 is an apocalyptic number.

It is an amenable number.

643551013 is a deficient number, since it is larger than the sum of its proper divisors (104873307).

643551013 is a wasteful number, since it uses less digits than its factorization.

643551013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3676.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 643551013 is about 25368.3072553137. The cubic root of 643551013 is about 863.3647759485.

The spelling of 643551013 in words is "six hundred forty-three million, five hundred fifty-one thousand, thirteen".