634421729 has 2 divisors, whose sum is σ = 634421730. Its totient is φ = 634421728.

The previous prime is 634421693. The next prime is 634421731. The reversal of 634421729 is 927124436.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 533379025 + 101042704 = 23095^2 + 10052^2 .

It is a cyclic number.

It is not a de Polignac number, because 634421729 - 2²⁴ = 617644513 is a prime.

Together with 634421731, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 634421692 and 634421701.

It is not a weakly prime, because it can be changed into another prime (634421779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 317210864 + 317210865.

It is an arithmetic number, because the mean of its divisors is an integer number (317210865).

Almost surely, 2^634421729 is an apocalyptic number.

It is an amenable number.

634421729 is a deficient number, since it is larger than the sum of its proper divisors (1).

634421729 is an equidigital number, since it uses as much as digits as its factorization.

634421729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 38.

The square root of 634421729 is about 25187.7297309623. The cubic root of 634421729 is about 859.2628120198.

The spelling of 634421729 in words is "six hundred thirty-four million, four hundred twenty-one thousand, seven hundred twenty-nine".