1221284357 has 2 divisors, whose sum is σ = 1221284358. Its totient is φ = 1221284356.

The previous prime is 1221284333. The next prime is 1221284359. The reversal of 1221284357 is 7534821221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1208674756 + 12609601 = 34766^2 + 3551^2 .

It is an emirp because it is prime and its reverse (7534821221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221284357 - 2⁸ = 1221284101 is a prime.

Together with 1221284359, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221284359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610642178 + 610642179.

It is an arithmetic number, because the mean of its divisors is an integer number (610642179).

Almost surely, 2^1221284357 is an apocalyptic number.

It is an amenable number.

1221284357 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221284357 is an equidigital number, since it uses as much as digits as its factorization.

1221284357 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 35.

The square root of 1221284357 is about 34946.8790738172. The cubic root of 1221284357 is about 1068.9045641190.

It can be divided in two parts, 12212 and 84357, that added together give a palindrome (96569).

The spelling of 1221284357 in words is "one billion, two hundred twenty-one million, two hundred eighty-four thousand, three hundred fifty-seven".