638544533 has 32 divisors (see below), whose sum is σ = 765072000. Its totient is φ = 526417920.

The previous prime is 638544527. The next prime is 638544559. The reversal of 638544533 is 335445836.

638544533 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 638544533 - 2¹⁸ = 638282389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638544233) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 829973 + ... + 830741.

It is an arithmetic number, because the mean of its divisors is an integer number (23908500).

Almost surely, 2^638544533 is an apocalyptic number.

It is an amenable number.

638544533 is a deficient number, since it is larger than the sum of its proper divisors (126527467).

638544533 is a wasteful number, since it uses less digits than its factorization.

638544533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 965.

The product of its digits is 518400, while the sum is 41.

The square root of 638544533 is about 25269.4387155710. The cubic root of 638544533 is about 861.1201075451.

The spelling of 638544533 in words is "six hundred thirty-eight million, five hundred forty-four thousand, five hundred thirty-three".