1665121 has 2 divisors, whose sum is σ = 1665122. Its totient is φ = 1665120.

The previous prime is 1665109. The next prime is 1665137. The reversal of 1665121 is 1215661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1661521 + 3600 = 1289^2 + 60^2 .

It is a cyclic number.

It is not a de Polignac number, because 1665121 - 2¹¹ = 1663073 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665092 and 1665101.

It is not a weakly prime, because it can be changed into another prime (1665161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832560 + 832561.

It is an arithmetic number, because the mean of its divisors is an integer number (832561).

2^1665121 is an apocalyptic number.

It is an amenable number.

1665121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665121 is an equidigital number, since it uses as much as digits as its factorization.

1665121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 22.

The square root of 1665121 is about 1290.3956757522. The cubic root of 1665121 is about 118.5264470041.

The spelling of 1665121 in words is "one million, six hundred sixty-five thousand, one hundred twenty-one".