639342137 has 16 divisors (see below), whose sum is σ = 777958272. Its totient is φ = 512904960.

The previous prime is 639342133. The next prime is 639342139. The reversal of 639342137 is 731243936.

639342137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639342137 - 2² = 639342133 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 639342137.

It is not an unprimeable number, because it can be changed into a prime (639342133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6698 + ... + 36380.

It is an arithmetic number, because the mean of its divisors is an integer number (48622392).

Almost surely, 2^639342137 is an apocalyptic number.

It is an amenable number.

639342137 is a deficient number, since it is larger than the sum of its proper divisors (138616135).

639342137 is a wasteful number, since it uses less digits than its factorization.

639342137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29888.

The product of its digits is 81648, while the sum is 38.

The square root of 639342137 is about 25285.2157791861. The cubic root of 639342137 is about 861.4784991850.

The spelling of 639342137 in words is "six hundred thirty-nine million, three hundred forty-two thousand, one hundred thirty-seven".