639329128847091 has 12 divisors (see below), whose sum is σ = 928310358119040. Its totient is φ = 423987903946320.

The previous prime is 639329128847081. The next prime is 639329128847093. The reversal of 639329128847091 is 190748821923936.

639329128847091 is a `hidden beast` number, since 6 + 3 + 9 + 3 + 29 + 128 + 8 + 470 + 9 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-639329128847091 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639329128847093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 185959605276 + ... + 185959608713.

It is an arithmetic number, because the mean of its divisors is an integer number (77359196509920).

Almost surely, 2^{639329128847091} is an apocalyptic number.

639329128847091 is a deficient number, since it is larger than the sum of its proper divisors (288981229271949).

639329128847091 is a wasteful number, since it uses less digits than its factorization.

639329128847091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371919214186 (or 371919214183 counting only the distinct ones).

The product of its (nonzero) digits is 282175488, while the sum is 72.

The spelling of 639329128847091 in words is "six hundred thirty-nine trillion, three hundred twenty-nine billion, one hundred twenty-eight million, eight hundred forty-seven thousand, ninety-one".