5172015721 has 2 divisors, whose sum is σ = 5172015722. Its totient is φ = 5172015720.

The previous prime is 5172015683. The next prime is 5172015731. The reversal of 5172015721 is 1275102715.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5167453225 + 4562496 = 71885^2 + 2136^2 .

It is a cyclic number.

It is not a de Polignac number, because 5172015721 - 2¹⁷ = 5171884649 is a prime.

It is a super-2 number, since 2×5172015721² = 53499493236542299682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (5172015731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2586007860 + 2586007861.

It is an arithmetic number, because the mean of its divisors is an integer number (2586007861).

Almost surely, 2^5172015721 is an apocalyptic number.

It is an amenable number.

5172015721 is a deficient number, since it is larger than the sum of its proper divisors (1).

5172015721 is an equidigital number, since it uses as much as digits as its factorization.

5172015721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4900, while the sum is 31.

The square root of 5172015721 is about 71916.7276855670. The cubic root of 5172015721 is about 1729.3647885690.

The spelling of 5172015721 in words is "five billion, one hundred seventy-two million, fifteen thousand, seven hundred twenty-one".