1661237 has 2 divisors, whose sum is σ = 1661238. Its totient is φ = 1661236.

The previous prime is 1661173. The next prime is 1661243. The reversal of 1661237 is 7321661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1615441 + 45796 = 1271^2 + 214^2 .

It is an emirp because it is prime and its reverse (7321661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1661237 - 2⁶ = 1661173 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661137) 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, 830618 + 830619.

It is an arithmetic number, because the mean of its divisors is an integer number (830619).

2^1661237 is an apocalyptic number.

It is an amenable number.

1661237 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661237 is an equidigital number, since it uses as much as digits as its factorization.

1661237 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 26.

The square root of 1661237 is about 1288.8898323751. The cubic root of 1661237 is about 118.4342184470.

Adding to 1661237 its reverse (7321661), we get a palindrome (8982898).

The spelling of 1661237 in words is "one million, six hundred sixty-one thousand, two hundred thirty-seven".