406661 has 2 divisors, whose sum is σ = 406662. Its totient is φ = 406660.

The previous prime is 406649. The next prime is 406673. The reversal of 406661 is 166604.

It is a balanced prime because it is at equal distance from previous prime (406649) and next prime (406673).

It can be written as a sum of positive squares in only one way, i.e., 220900 + 185761 = 470^2 + 431^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-406661 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (406631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203330 + 203331.

It is an arithmetic number, because the mean of its divisors is an integer number (203331).

2⁴⁰⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

406661 is a deficient number, since it is larger than the sum of its proper divisors (1).

406661 is an equidigital number, since it uses as much as digits as its factorization.

406661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 406661 is about 637.6997726203. The cubic root of 406661 is about 74.0873694129.

The spelling of 406661 in words is "four hundred six thousand, six hundred sixty-one".