639680729193 has 80 divisors (see below), whose sum is σ = 1050651866880. Its totient is φ = 384639840000.

The previous prime is 639680729173. The next prime is 639680729197. The reversal of 639680729193 is 391927086936.

639680729193 is a `hidden beast` number, since 6 + 396 + 8 + 0 + 72 + 91 + 93 = 666.

It is not a de Polignac number, because 639680729193 - 2²⁴ = 639663951977 is a prime.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 639680729193.

It is not an unprimeable number, because it can be changed into a prime (639680729197) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 105052093 + ... + 105058181.

It is an arithmetic number, because the mean of its divisors is an integer number (13133148336).

Almost surely, 2^639680729193 is an apocalyptic number.

It is an amenable number.

639680729193 is a deficient number, since it is larger than the sum of its proper divisors (410971137687).

639680729193 is a wasteful number, since it uses less digits than its factorization.

639680729193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7020 (or 7011 counting only the distinct ones).

The product of its (nonzero) digits is 26453952, while the sum is 63.

The spelling of 639680729193 in words is "six hundred thirty-nine billion, six hundred eighty million, seven hundred twenty-nine thousand, one hundred ninety-three".