1213643 has 2 divisors, whose sum is σ = 1213644. Its totient is φ = 1213642.

The previous prime is 1213633. The next prime is 1213651. The reversal of 1213643 is 3463121.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1213643 - 2⁴ = 1213627 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1213633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606821 + 606822.

It is an arithmetic number, because the mean of its divisors is an integer number (606822).

2^1213643 is an apocalyptic number.

1213643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213643 is an equidigital number, since it uses as much as digits as its factorization.

1213643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 20.

The square root of 1213643 is about 1101.6546645841. The cubic root of 1213643 is about 106.6670583753.

Adding to 1213643 its reverse (3463121), we get a palindrome (4676764).

The spelling of 1213643 in words is "one million, two hundred thirteen thousand, six hundred forty-three".