1228691 has 2 divisors, whose sum is σ = 1228692. Its totient is φ = 1228690.

The previous prime is 1228679. The next prime is 1228693. The reversal of 1228691 is 1968221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1228691 - 2¹⁸ = 966547 is a prime.

It is a Sophie Germain prime.

Together with 1228693, 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 (1228693) 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, 614345 + 614346.

It is an arithmetic number, because the mean of its divisors is an integer number (614346).

2^1228691 is an apocalyptic number.

1228691 is a deficient number, since it is larger than the sum of its proper divisors (1).

1228691 is an equidigital number, since it uses as much as digits as its factorization.

1228691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 1228691 is about 1108.4633507699. The cubic root of 1228691 is about 107.1061048973.

The spelling of 1228691 in words is "one million, two hundred twenty-eight thousand, six hundred ninety-one".