3118721 has 2 divisors, whose sum is σ = 3118722. Its totient is φ = 3118720.

The previous prime is 3118699. The next prime is 3118723. The reversal of 3118721 is 1278113.

It is a happy number.

3118721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2676496 + 442225 = 1636^2 + 665^2 .

It is an emirp because it is prime and its reverse (1278113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3118721 - 2⁶ = 3118657 is a prime.

It is a Sophie Germain prime.

Together with 3118723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p₂₂₄₇₆₂ and since 3118721 and 224762 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (3118723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1559360 + 1559361.

It is an arithmetic number, because the mean of its divisors is an integer number (1559361).

Almost surely, 2^3118721 is an apocalyptic number.

It is an amenable number.

3118721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3118721 is an equidigital number, since it uses as much as digits as its factorization.

3118721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 336, while the sum is 23.

The square root of 3118721 is about 1765.9900905724. The cubic root of 3118721 is about 146.1029017488.

The spelling of 3118721 in words is "three million, one hundred eighteen thousand, seven hundred twenty-one".