634920728137 has 2 divisors, whose sum is σ = 634920728138. Its totient is φ = 634920728136.

The previous prime is 634920728129. The next prime is 634920728201. The reversal of 634920728137 is 731827029436.

634920728137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 537903429561 + 97017298576 = 733419^2 + 311476^2 .

It is a cyclic number.

It is not a de Polignac number, because 634920728137 - 2³ = 634920728129 is a prime.

It is not a weakly prime, because it can be changed into another prime (634920723137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317460364068 + 317460364069.

It is an arithmetic number, because the mean of its divisors is an integer number (317460364069).

Almost surely, 2^634920728137 is an apocalyptic number.

It is an amenable number.

634920728137 is a deficient number, since it is larger than the sum of its proper divisors (1).

634920728137 is an equidigital number, since it uses as much as digits as its factorization.

634920728137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3048192, while the sum is 52.

The spelling of 634920728137 in words is "six hundred thirty-four billion, nine hundred twenty million, seven hundred twenty-eight thousand, one hundred thirty-seven".