1661069 has 2 divisors, whose sum is σ = 1661070. Its totient is φ = 1661068.

The previous prime is 1661063. The next prime is 1661111. The reversal of 1661069 is 9601661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1295044 + 366025 = 1138^2 + 605^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661069 is a prime.

It is a super-2 number, since 2×1661069² = 5518300445522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830534 + 830535.

It is an arithmetic number, because the mean of its divisors is an integer number (830535).

2^1661069 is an apocalyptic number.

It is an amenable number.

1661069 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661069 is an equidigital number, since it uses as much as digits as its factorization.

1661069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 1661069 is about 1288.8246583613. The cubic root of 1661069 is about 118.4302259162.

The spelling of 1661069 in words is "one million, six hundred sixty-one thousand, sixty-nine".