639650733 has 4 divisors (see below), whose sum is σ = 852867648. Its totient is φ = 426433820.

The previous prime is 639650731. The next prime is 639650749. The reversal of 639650733 is 337056936.

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 639650733 - 2¹ = 639650731 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639650731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106608453 + ... + 106608458.

It is an arithmetic number, because the mean of its divisors is an integer number (213216912).

Almost surely, 2^639650733 is an apocalyptic number.

It is an amenable number.

639650733 is a deficient number, since it is larger than the sum of its proper divisors (213216915).

639650733 is a wasteful number, since it uses less digits than its factorization.

639650733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213216914.

The product of its (nonzero) digits is 306180, while the sum is 42.

The square root of 639650733 is about 25291.3173441005. The cubic root of 639650733 is about 861.6170822909.

The spelling of 639650733 in words is "six hundred thirty-nine million, six hundred fifty thousand, seven hundred thirty-three".