1213304621 has 2 divisors, whose sum is σ = 1213304622. Its totient is φ = 1213304620.

The previous prime is 1213304593. The next prime is 1213304623. The reversal of 1213304621 is 1264033121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1128019396 + 85285225 = 33586^2 + 9235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213304621 - 2¹⁸ = 1213042477 is a prime.

It is a Sophie Germain prime.

Together with 1213304623, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1213304623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606652310 + 606652311.

It is an arithmetic number, because the mean of its divisors is an integer number (606652311).

Almost surely, 2^1213304621 is an apocalyptic number.

It is an amenable number.

1213304621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213304621 is an equidigital number, since it uses as much as digits as its factorization.

1213304621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 1213304621 is about 34832.5224610564. The cubic root of 1213304621 is about 1066.5714407937.

Adding to 1213304621 its reverse (1264033121), we get a palindrome (2477337742).

The spelling of 1213304621 in words is "one billion, two hundred thirteen million, three hundred four thousand, six hundred twenty-one".