639216733 has 4 divisors (see below), whose sum is σ = 641891520. Its totient is φ = 636541948.

The previous prime is 639216731. The next prime is 639216749. The reversal of 639216733 is 337612936.

639216733 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 639216733 - 2¹ = 639216731 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639216731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1337035 + ... + 1337512.

It is an arithmetic number, because the mean of its divisors is an integer number (160472880).

Almost surely, 2^639216733 is an apocalyptic number.

It is an amenable number.

639216733 is a deficient number, since it is larger than the sum of its proper divisors (2674787).

639216733 is a wasteful number, since it uses less digits than its factorization.

639216733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2674786.

The product of its digits is 122472, while the sum is 40.

The square root of 639216733 is about 25282.7358685725. The cubic root of 639216733 is about 861.4221704957.

The spelling of 639216733 in words is "six hundred thirty-nine million, two hundred sixteen thousand, seven hundred thirty-three".