1661347 has 2 divisors, whose sum is σ = 1661348. Its totient is φ = 1661346.

The previous prime is 1661333. The next prime is 1661353. The reversal of 1661347 is 7431661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1661347 - 2¹¹ = 1659299 is a prime.

It is not a weakly prime, because it can be changed into another prime (1661327) 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, 830673 + 830674.

It is an arithmetic number, because the mean of its divisors is an integer number (830674).

2^1661347 is an apocalyptic number.

1661347 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661347 is an equidigital number, since it uses as much as digits as its factorization.

1661347 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 1661347 is about 1288.9325040513. The cubic root of 1661347 is about 118.4368324582.

The spelling of 1661347 in words is "one million, six hundred sixty-one thousand, three hundred forty-seven".