1665271 has 2 divisors, whose sum is σ = 1665272. Its totient is φ = 1665270.

The previous prime is 1665263. The next prime is 1665277. The reversal of 1665271 is 1725661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1665271 - 2³ = 1665263 is a prime.

It is a Chen prime.

It is an Ulam number.

1665271 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832635 + 832636.

It is an arithmetic number, because the mean of its divisors is an integer number (832636).

2^1665271 is an apocalyptic number.

1665271 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665271 is an equidigital number, since it uses as much as digits as its factorization.

1665271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2520, while the sum is 28.

The square root of 1665271 is about 1290.4537961508. The cubic root of 1665271 is about 118.5300059913.

It can be divided in two parts, 1665 and 271, that added together give a square (1936 = 44²).

The spelling of 1665271 in words is "one million, six hundred sixty-five thousand, two hundred seventy-one".