637420 has 48 divisors (see below), whose sum is σ = 1592640. Its totient is φ = 209664.

The previous prime is 637409. The next prime is 637421. The reversal of 637420 is 24736.

637420 = T₁₉₅ + T₁₉₆ + ... + T₂₂₃.

It is a junction number, because it is equal to n+sod(n) for n = 637391 and 637400.

It is not an unprimeable number, because it can be changed into a prime (637421) by changing a digit.

637420 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 15 ways as a sum of consecutive naturals, for example, 3982 + ... + 4138.

It is an arithmetic number, because the mean of its divisors is an integer number (33180).

2⁶³⁷⁴²⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 637420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (796320).

637420 is an abundant number, since it is smaller than the sum of its proper divisors (955220).

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

637420 is a wasteful number, since it uses less digits than its factorization.

637420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 200 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 637420 is about 798.3858716185. The cubic root of 637420 is about 86.0614307798.

The spelling of 637420 in words is "six hundred thirty-seven thousand, four hundred twenty".