406638 has 48 divisors (see below), whose sum is σ = 982800. Its totient is φ = 120960.

The previous prime is 406633. The next prime is 406649. The reversal of 406638 is 836604.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 406638.

It is not an unprimeable number, because it can be changed into a prime (406631) by changing a digit.

406638 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 23 ways as a sum of consecutive naturals, for example, 9898 + ... + 9938.

It is an arithmetic number, because the mean of its divisors is an integer number (20475).

2⁴⁰⁶⁶³⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 406638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (491400).

406638 is an abundant number, since it is smaller than the sum of its proper divisors (576162).

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

406638 is a wasteful number, since it uses less digits than its factorization.

406638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 406638 is about 637.6817388008. The cubic root of 406638 is about 74.0859726380.

The spelling of 406638 in words is "four hundred six thousand, six hundred thirty-eight".