10008205721 has 2 divisors, whose sum is σ = 10008205722. Its totient is φ = 10008205720.

The previous prime is 10008205703. The next prime is 10008205729. The reversal of 10008205721 is 12750280001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6932394121 + 3075811600 = 83261^2 + 55460^2 .

It is a cyclic number.

It is not a de Polignac number, because 10008205721 - 2¹⁴ = 10008189337 is a prime.

It is not a weakly prime, because it can be changed into another prime (10008205729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5004102860 + 5004102861.

It is an arithmetic number, because the mean of its divisors is an integer number (5004102861).

Almost surely, 2^10008205721 is an apocalyptic number.

It is an amenable number.

10008205721 is a deficient number, since it is larger than the sum of its proper divisors (1).

10008205721 is an equidigital number, since it uses as much as digits as its factorization.

10008205721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1120, while the sum is 26.

Adding to 10008205721 its reverse (12750280001), we get a palindrome (22758485722).

The spelling of 10008205721 in words is "ten billion, eight million, two hundred five thousand, seven hundred twenty-one".