1221043247 has 2 divisors, whose sum is σ = 1221043248. Its totient is φ = 1221043246.

The previous prime is 1221043223. The next prime is 1221043259. The reversal of 1221043247 is 7423401221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221043247 - 2⁶ = 1221043183 is a prime.

It is a super-2 number, since 2×1221043247² = 2981893222088606018, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221043217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610521623 + 610521624.

It is an arithmetic number, because the mean of its divisors is an integer number (610521624).

Almost surely, 2^1221043247 is an apocalyptic number.

1221043247 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221043247 is an equidigital number, since it uses as much as digits as its factorization.

1221043247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 26.

The square root of 1221043247 is about 34943.4292392719. The cubic root of 1221043247 is about 1068.8342172638.

Adding to 1221043247 its reverse (7423401221), we get a palindrome (8644444468).

The spelling of 1221043247 in words is "one billion, two hundred twenty-one million, forty-three thousand, two hundred forty-seven".