3145721 has 2 divisors, whose sum is σ = 3145722. Its totient is φ = 3145720.

The previous prime is 3145711. The next prime is 3145739. The reversal of 3145721 is 1275413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2676496 + 469225 = 1636^2 + 685^2 .

It is a cyclic number.

It is not a de Polignac number, because 3145721 - 2¹⁰ = 3144697 is a prime.

It is not a weakly prime, because it can be changed into another prime (3145711) 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, 1572860 + 1572861.

It is an arithmetic number, because the mean of its divisors is an integer number (1572861).

Almost surely, 2^3145721 is an apocalyptic number.

It is an amenable number.

3145721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3145721 is an equidigital number, since it uses as much as digits as its factorization.

3145721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 3145721 is about 1773.6180535843. The cubic root of 3145721 is about 146.5233143635.

The spelling of 3145721 in words is "three million, one hundred forty-five thousand, seven hundred twenty-one".