1665143 has 2 divisors, whose sum is σ = 1665144. Its totient is φ = 1665142.

The previous prime is 1665137. The next prime is 1665149. The reversal of 1665143 is 3415661.

It is a balanced prime because it is at equal distance from previous prime (1665137) and next prime (1665149).

It is a cyclic number.

It is not a de Polignac number, because 1665143 - 2¹⁶ = 1599607 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is equal to p₁₂₅₆₈₄ and since 1665143 and 125684 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832571 + 832572.

It is an arithmetic number, because the mean of its divisors is an integer number (832572).

2^1665143 is an apocalyptic number.

1665143 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665143 is an equidigital number, since it uses as much as digits as its factorization.

1665143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 26.

The square root of 1665143 is about 1290.4042002411. The cubic root of 1665143 is about 118.5269690023.

The spelling of 1665143 in words is "one million, six hundred sixty-five thousand, one hundred forty-three".