3720351721 has 2 divisors, whose sum is σ = 3720351722. Its totient is φ = 3720351720.

The previous prime is 3720351697. The next prime is 3720351737. The reversal of 3720351721 is 1271530273.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3713196096 + 7155625 = 60936^2 + 2675^2 .

It is a cyclic number.

It is not a de Polignac number, because 3720351721 - 2⁹ = 3720351209 is a prime.

It is not a weakly prime, because it can be changed into another prime (3720351121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1860175860 + 1860175861.

It is an arithmetic number, because the mean of its divisors is an integer number (1860175861).

Almost surely, 2^3720351721 is an apocalyptic number.

It is an amenable number.

3720351721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3720351721 is an equidigital number, since it uses as much as digits as its factorization.

3720351721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 3720351721 is about 60994.6860062416. The cubic root of 3720351721 is about 1549.5110106490.

Adding to 3720351721 its reverse (1271530273), we get a palindrome (4991881994).

The spelling of 3720351721 in words is "three billion, seven hundred twenty million, three hundred fifty-one thousand, seven hundred twenty-one".