1221204947 has 2 divisors, whose sum is σ = 1221204948. Its totient is φ = 1221204946.

The previous prime is 1221204931. The next prime is 1221204973. The reversal of 1221204947 is 7494021221.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221204947 - 2⁴ = 1221204931 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221204847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610602473 + 610602474.

It is an arithmetic number, because the mean of its divisors is an integer number (610602474).

Almost surely, 2^1221204947 is an apocalyptic number.

1221204947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221204947 is an equidigital number, since it uses as much as digits as its factorization.

1221204947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 1221204947 is about 34945.7429023908. The cubic root of 1221204947 is about 1068.8813962818.

The spelling of 1221204947 in words is "one billion, two hundred twenty-one million, two hundred four thousand, nine hundred forty-seven".