1221767 has 2 divisors, whose sum is σ = 1221768. Its totient is φ = 1221766.

The previous prime is 1221761. The next prime is 1221791. The reversal of 1221767 is 7671221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221767 - 2⁴ = 1221751 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 (1221761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610883 + 610884.

It is an arithmetic number, because the mean of its divisors is an integer number (610884).

2^1221767 is an apocalyptic number.

1221767 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221767 is an equidigital number, since it uses as much as digits as its factorization.

1221767 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1176, while the sum is 26.

The square root of 1221767 is about 1105.3356956147. The cubic root of 1221767 is about 106.9045353433.

Adding to 1221767 its reverse (7671221), we get a palindrome (8892988).

The spelling of 1221767 in words is "one million, two hundred twenty-one thousand, seven hundred sixty-seven".