1221388667 has 2 divisors, whose sum is σ = 1221388668. Its totient is φ = 1221388666.

The previous prime is 1221388661. The next prime is 1221388673. The reversal of 1221388667 is 7668831221.

It is a balanced prime because it is at equal distance from previous prime (1221388661) and next prime (1221388673).

It is a cyclic number.

It is not a de Polignac number, because 1221388667 - 2⁶ = 1221388603 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221388661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610694333 + 610694334.

It is an arithmetic number, because the mean of its divisors is an integer number (610694334).

Almost surely, 2^1221388667 is an apocalyptic number.

1221388667 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221388667 is an equidigital number, since it uses as much as digits as its factorization.

1221388667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 193536, while the sum is 44.

The square root of 1221388667 is about 34948.3714498973. The cubic root of 1221388667 is about 1068.9349949956.

The spelling of 1221388667 in words is "one billion, two hundred twenty-one million, three hundred eighty-eight thousand, six hundred sixty-seven".