406656 has 48 divisors (see below), whose sum is σ = 1173510. Its totient is φ = 135168.

The previous prime is 406649. The next prime is 406661. The reversal of 406656 is 656604.

406656 is a `hidden beast` number, since 4 + 0 + 6 + 656 = 666.

It can be written as a sum of positive squares in only one way, i.e., 360000 + 46656 = 600^2 + 216^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 976 + ... + 1328.

2⁴⁰⁶⁶⁵⁶ 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 406656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (586755).

406656 is an abundant number, since it is smaller than the sum of its proper divisors (766854).

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

406656 is a wasteful number, since it uses less digits than its factorization.

406656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373 (or 358 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 406656 is about 637.6958522681. The cubic root of 406656 is about 74.0870657707.

The spelling of 406656 in words is "four hundred six thousand, six hundred fifty-six".