1221000947 has 2 divisors, whose sum is σ = 1221000948. Its totient is φ = 1221000946.

The previous prime is 1221000941. The next prime is 1221000967. The reversal of 1221000947 is 7490001221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221000947 - 2⁸ = 1221000691 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221000941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610500473 + 610500474.

It is an arithmetic number, because the mean of its divisors is an integer number (610500474).

Almost surely, 2^1221000947 is an apocalyptic number.

1221000947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221000947 is an equidigital number, since it uses as much as digits as its factorization.

1221000947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 26.

The square root of 1221000947 is about 34942.8239700228. The cubic root of 1221000947 is about 1068.8218747554.

The spelling of 1221000947 in words is "one billion, two hundred twenty-one million, nine hundred forty-seven", and thus it is an aban number.