639320221 has 8 divisors (see below), whose sum is σ = 642961088. Its totient is φ = 635688000.

The previous prime is 639320191. The next prime is 639320243. The reversal of 639320221 is 122023936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 639320221 - 2¹³ = 639312029 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639320221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639320251) 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 7 ways as a sum of consecutive naturals, for example, 193816 + ... + 197086.

It is an arithmetic number, because the mean of its divisors is an integer number (80370136).

Almost surely, 2^639320221 is an apocalyptic number.

It is an amenable number.

639320221 is a deficient number, since it is larger than the sum of its proper divisors (3640867).

639320221 is a wasteful number, since it uses less digits than its factorization.

639320221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4323.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 639320221 is about 25284.7823996965. The cubic root of 639320221 is about 861.4686555361.

The spelling of 639320221 in words is "six hundred thirty-nine million, three hundred twenty thousand, two hundred twenty-one".