634989 has 4 divisors (see below), whose sum is σ = 846656. Its totient is φ = 423324.

The previous prime is 634979. The next prime is 635003. The reversal of 634989 is 989436.

634989 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 634989 - 2⁷ = 634861 is a prime.

It is a super-2 number, since 2×634989² = 806422060242, which contains 22 as substring.

It is a D-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 (634939) 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, 105829 + ... + 105834.

It is an arithmetic number, because the mean of its divisors is an integer number (211664).

2⁶³⁴⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

634989 is a deficient number, since it is larger than the sum of its proper divisors (211667).

634989 is a wasteful number, since it uses less digits than its factorization.

634989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211666.

The product of its digits is 46656, while the sum is 39.

The square root of 634989 is about 796.8619704817. The cubic root of 634989 is about 85.9518840276.

The spelling of 634989 in words is "six hundred thirty-four thousand, nine hundred eighty-nine".