1966409 has 2 divisors, whose sum is σ = 1966410. Its totient is φ = 1966408.

The previous prime is 1966399. The next prime is 1966417. The reversal of 1966409 is 9046691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1006009 + 960400 = 1003^2 + 980^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1966409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1966429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983204 + 983205.

It is an arithmetic number, because the mean of its divisors is an integer number (983205).

2^1966409 is an apocalyptic number.

It is an amenable number.

1966409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1966409 is an equidigital number, since it uses as much as digits as its factorization.

1966409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 1966409 is about 1402.2870604837. The cubic root of 1966409 is about 125.2827519285.

The spelling of 1966409 in words is "one million, nine hundred sixty-six thousand, four hundred nine".