1221204847 has 2 divisors, whose sum is σ = 1221204848. Its totient is φ = 1221204846.

The previous prime is 1221204821. The next prime is 1221204893. The reversal of 1221204847 is 7484021221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221204847 - 2¹¹ = 1221202799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221204947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610602423 + 610602424.

It is an arithmetic number, because the mean of its divisors is an integer number (610602424).

Almost surely, 2^1221204847 is an apocalyptic number.

1221204847 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221204847 is an equidigital number, since it uses as much as digits as its factorization.

1221204847 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 1221204847 is about 34945.7414716014. The cubic root of 1221204847 is about 1068.8813671062.

The spelling of 1221204847 in words is "one billion, two hundred twenty-one million, two hundred four thousand, eight hundred forty-seven".