634521 has 4 divisors (see below), whose sum is σ = 846032. Its totient is φ = 423012.

The previous prime is 634519. The next prime is 634523. The reversal of 634521 is 125436.

It is a happy number.

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 an interprime number because it is at equal distance from previous prime (634519) and next prime (634523).

It is not a de Polignac number, because 634521 - 2¹ = 634519 is a prime.

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 Curzon number.

It is not an unprimeable number, because it can be changed into a prime (634523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 105751 + ... + 105756.

It is an arithmetic number, because the mean of its divisors is an integer number (211508).

2⁶³⁴⁵²¹ is an apocalyptic number.

It is an amenable number.

634521 is a deficient number, since it is larger than the sum of its proper divisors (211511).

634521 is a wasteful number, since it uses less digits than its factorization.

634521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211510.

The product of its digits is 720, while the sum is 21.

The square root of 634521 is about 796.5682644946. The cubic root of 634521 is about 85.9307627335.

Adding to 634521 its reverse (125436), we get a palindrome (759957).

The spelling of 634521 in words is "six hundred thirty-four thousand, five hundred twenty-one".