1236661 has 2 divisors, whose sum is σ = 1236662. Its totient is φ = 1236660.

The previous prime is 1236659. The next prime is 1236667. The reversal of 1236661 is 1666321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1199025 + 37636 = 1095^2 + 194^2 .

It is an emirp because it is prime and its reverse (1666321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1236661 - 2¹ = 1236659 is a prime.

Together with 1236659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1236667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 618330 + 618331.

It is an arithmetic number, because the mean of its divisors is an integer number (618331).

2^1236661 is an apocalyptic number.

It is an amenable number.

1236661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1236661 is an equidigital number, since it uses as much as digits as its factorization.

1236661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 25.

The square root of 1236661 is about 1112.0526066693. The cubic root of 1236661 is about 107.3371899990.

The spelling of 1236661 in words is "one million, two hundred thirty-six thousand, six hundred sixty-one".