3171487721 has 2 divisors, whose sum is σ = 3171487722. Its totient is φ = 3171487720.

The previous prime is 3171487699. The next prime is 3171487757. The reversal of 3171487721 is 1277841713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2671339225 + 500148496 = 51685^2 + 22364^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3171487721 is a prime.

It is not a weakly prime, because it can be changed into another prime (3171480721) 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, 1585743860 + 1585743861.

It is an arithmetic number, because the mean of its divisors is an integer number (1585743861).

Almost surely, 2^3171487721 is an apocalyptic number.

It is an amenable number.

3171487721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3171487721 is an equidigital number, since it uses as much as digits as its factorization.

3171487721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 65856, while the sum is 41.

The square root of 3171487721 is about 56315.9632875085. The cubic root of 3171487721 is about 1469.2228636355. Note that the first 3 decimals are identical.

The spelling of 3171487721 in words is "three billion, one hundred seventy-one million, four hundred eighty-seven thousand, seven hundred twenty-one".