3118951721 has 2 divisors, whose sum is σ = 3118951722. Its totient is φ = 3118951720.

The previous prime is 3118951681. The next prime is 3118951763. The reversal of 3118951721 is 1271598113.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2946318400 + 172633321 = 54280^2 + 13139^2 .

It is a cyclic number.

It is not a de Polignac number, because 3118951721 - 2¹⁰ = 3118950697 is a prime.

It is not a weakly prime, because it can be changed into another prime (3118951921) 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, 1559475860 + 1559475861.

It is an arithmetic number, because the mean of its divisors is an integer number (1559475861).

Almost surely, 2^3118951721 is an apocalyptic number.

It is an amenable number.

3118951721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3118951721 is an equidigital number, since it uses as much as digits as its factorization.

3118951721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 38.

The square root of 3118951721 is about 55847.5757844510. The cubic root of 3118951721 is about 1461.0650452655.

The spelling of 3118951721 in words is "three billion, one hundred eighteen million, nine hundred fifty-one thousand, seven hundred twenty-one".