5171539721 has 2 divisors, whose sum is σ = 5171539722. Its totient is φ = 5171539720.

The previous prime is 5171539717. The next prime is 5171539727. The reversal of 5171539721 is 1279351715.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3306250000 + 1865289721 = 57500^2 + 43189^2 .

It is a cyclic number.

It is not a de Polignac number, because 5171539721 - 2² = 5171539717 is a prime.

It is not a weakly prime, because it can be changed into another prime (5171539727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2585769860 + 2585769861.

It is an arithmetic number, because the mean of its divisors is an integer number (2585769861).

Almost surely, 2^5171539721 is an apocalyptic number.

It is an amenable number.

5171539721 is a deficient number, since it is larger than the sum of its proper divisors (1).

5171539721 is an equidigital number, since it uses as much as digits as its factorization.

5171539721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 66150, while the sum is 41.

The square root of 5171539721 is about 71913.4182263644. The cubic root of 5171539721 is about 1729.3117336327.

The spelling of 5171539721 in words is "five billion, one hundred seventy-one million, five hundred thirty-nine thousand, seven hundred twenty-one".