8538225721 has 2 divisors, whose sum is σ = 8538225722. Its totient is φ = 8538225720.

The previous prime is 8538225697. The next prime is 8538225737. The reversal of 8538225721 is 1275228358.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5908074496 + 2630151225 = 76864^2 + 51285^2 .

It is a cyclic number.

It is not a de Polignac number, because 8538225721 - 2¹⁵ = 8538192953 is a prime.

It is not a weakly prime, because it can be changed into another prime (8538225221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4269112860 + 4269112861.

It is an arithmetic number, because the mean of its divisors is an integer number (4269112861).

Almost surely, 2^8538225721 is an apocalyptic number.

It is an amenable number.

8538225721 is a deficient number, since it is larger than the sum of its proper divisors (1).

8538225721 is an equidigital number, since it uses as much as digits as its factorization.

8538225721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 268800, while the sum is 43.

The square root of 8538225721 is about 92402.5201009150. The cubic root of 8538225721 is about 2043.8822745662.

The spelling of 8538225721 in words is "eight billion, five hundred thirty-eight million, two hundred twenty-five thousand, seven hundred twenty-one".