635420 has 12 divisors (see below), whose sum is σ = 1334424. Its totient is φ = 254160.

The previous prime is 635413. The next prime is 635423. The reversal of 635420 is 24536.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 31771 = 635420 / (6 + 3 + 5 + 4 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 635392 and 635401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (635423) by changing a digit.

635420 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15866 + ... + 15905.

It is an arithmetic number, because the mean of its divisors is an integer number (111202).

2⁶³⁵⁴²⁰ is an apocalyptic number.

It is an amenable number.

635420 is an abundant number, since it is smaller than the sum of its proper divisors (699004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

635420 is a wasteful number, since it uses less digits than its factorization.

635420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31780 (or 31778 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 20.

The square root of 635420 is about 797.1323604020. The cubic root of 635420 is about 85.9713262980.

Adding to 635420 its reverse (24536), we get a palindrome (659956).

The spelling of 635420 in words is "six hundred thirty-five thousand, four hundred twenty".