1966999 has 2 divisors, whose sum is σ = 1967000. Its totient is φ = 1966998.

The previous prime is 1966973. The next prime is 1967011. The reversal of 1966999 is 9996691.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1966999 - 2⁵ = 1966967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1966399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 983499 + 983500.

It is an arithmetic number, because the mean of its divisors is an integer number (983500).

2^1966999 is an apocalyptic number.

1966999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1966999 is an equidigital number, since it uses as much as digits as its factorization.

1966999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 236196, while the sum is 49.

The square root of 1966999 is about 1402.4974153274. The cubic root of 1966999 is about 125.2952805924.

The spelling of 1966999 in words is "one million, nine hundred sixty-six thousand, nine hundred ninety-nine".