1221021304357 has 2 divisors, whose sum is σ = 1221021304358. Its totient is φ = 1221021304356.

The previous prime is 1221021304309. The next prime is 1221021304369. The reversal of 1221021304357 is 7534031201221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 938081354116 + 282939950241 = 968546^2 + 531921^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221021304357 - 2³⁵ = 1186661565989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221021308357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610510652178 + 610510652179.

It is an arithmetic number, because the mean of its divisors is an integer number (610510652179).

Almost surely, 2^{1221021304357} is an apocalyptic number.

It is an amenable number.

1221021304357 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221021304357 is an equidigital number, since it uses as much as digits as its factorization.

1221021304357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 31.

Adding to 1221021304357 its reverse (7534031201221), we get a palindrome (8755052505578).

The spelling of 1221021304357 in words is "one trillion, two hundred twenty-one billion, twenty-one million, three hundred four thousand, three hundred fifty-seven".