634909 has 4 divisors (see below), whose sum is σ = 692640. Its totient is φ = 577180.

The previous prime is 634903. The next prime is 634927. The reversal of 634909 is 909436.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 634909 - 2³ = 634901 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (634901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28849 + ... + 28870.

It is an arithmetic number, because the mean of its divisors is an integer number (173160).

2⁶³⁴⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

634909 is a deficient number, since it is larger than the sum of its proper divisors (57731).

634909 is a wasteful number, since it uses less digits than its factorization.

634909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57730.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 634909 is about 796.8117720014. The cubic root of 634909 is about 85.9482742855.

The spelling of 634909 in words is "six hundred thirty-four thousand, nine hundred nine".