3159721 has 2 divisors, whose sum is σ = 3159722. Its totient is φ = 3159720.

The previous prime is 3159707. The next prime is 3159733. The reversal of 3159721 is 1279513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2576025 + 583696 = 1605^2 + 764^2 .

It is a cyclic number.

It is not a de Polignac number, because 3159721 - 2⁹ = 3159209 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3159721.

It is not a weakly prime, because it can be changed into another prime (3159781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1579860 + 1579861.

It is an arithmetic number, because the mean of its divisors is an integer number (1579861).

Almost surely, 2^3159721 is an apocalyptic number.

It is an amenable number.

3159721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3159721 is an equidigital number, since it uses as much as digits as its factorization.

3159721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1890, while the sum is 28.

The square root of 3159721 is about 1777.5604068498. The cubic root of 3159721 is about 146.7403595461.

The spelling of 3159721 in words is "three million, one hundred fifty-nine thousand, seven hundred twenty-one".