1661249 has 2 divisors, whose sum is σ = 1661250. Its totient is φ = 1661248.

The previous prime is 1661243. The next prime is 1661251. The reversal of 1661249 is 9421661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1364224 + 297025 = 1168^2 + 545^2 .

It is an emirp because it is prime and its reverse (9421661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1661249 - 2¹² = 1657153 is a prime.

Together with 1661251, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1661243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 830624 + 830625.

It is an arithmetic number, because the mean of its divisors is an integer number (830625).

2^1661249 is an apocalyptic number.

It is an amenable number.

1661249 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661249 is an equidigital number, since it uses as much as digits as its factorization.

1661249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 29.

The square root of 1661249 is about 1288.8944875357. The cubic root of 1661249 is about 118.4345036174.

It can be divided in two parts, 16612 and 49, that added together give a palindrome (16661).

The spelling of 1661249 in words is "one million, six hundred sixty-one thousand, two hundred forty-nine".