3213130721 has 2 divisors, whose sum is σ = 3213130722. Its totient is φ = 3213130720.

The previous prime is 3213130709. The next prime is 3213130787. The reversal of 3213130721 is 1270313123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2449161121 + 763969600 = 49489^2 + 27640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3213130721 is a prime.

It is not a weakly prime, because it can be changed into another prime (3213330721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1606565360 + 1606565361.

It is an arithmetic number, because the mean of its divisors is an integer number (1606565361).

Almost surely, 2^3213130721 is an apocalyptic number.

It is an amenable number.

3213130721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3213130721 is an equidigital number, since it uses as much as digits as its factorization.

3213130721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 3213130721 is about 56684.4839528420. The cubic root of 3213130721 is about 1475.6254317496.

Adding to 3213130721 its reverse (1270313123), we get a palindrome (4483443844).

The spelling of 3213130721 in words is "three billion, two hundred thirteen million, one hundred thirty thousand, seven hundred twenty-one".