1221031313 has 2 divisors, whose sum is σ = 1221031314. Its totient is φ = 1221031312.

The previous prime is 1221031297. The next prime is 1221031321. The reversal of 1221031313 is 3131301221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 873320704 + 347710609 = 29552^2 + 18647^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221031313 - 2⁴ = 1221031297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221031291 and 1221031300.

It is not a weakly prime, because it can be changed into another prime (1221031363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610515656 + 610515657.

It is an arithmetic number, because the mean of its divisors is an integer number (610515657).

Almost surely, 2^1221031313 is an apocalyptic number.

It is an amenable number.

1221031313 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221031313 is an equidigital number, since it uses as much as digits as its factorization.

1221031313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1221031313 is about 34943.2584771369. The cubic root of 1221031313 is about 1068.8307351296.

Adding to 1221031313 its reverse (3131301221), we get a palindrome (4352332534).

The spelling of 1221031313 in words is "one billion, two hundred twenty-one million, thirty-one thousand, three hundred thirteen".