20002001121721 has 2 divisors, whose sum is σ = 20002001121722. Its totient is φ = 20002001121720.

The previous prime is 20002001121701. The next prime is 20002001121737. The reversal of 20002001121721 is 12712110020002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17458725716496 + 2543275405225 = 4178364^2 + 1594765^2 .

It is a cyclic number.

It is not a de Polignac number, because 20002001121721 - 2⁵ = 20002001121689 is a prime.

It is not a weakly prime, because it can be changed into another prime (20002001121701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001000560860 + 10001000560861.

It is an arithmetic number, because the mean of its divisors is an integer number (10001000560861).

Almost surely, 2^{20002001121721} is an apocalyptic number.

It is an amenable number.

20002001121721 is a deficient number, since it is larger than the sum of its proper divisors (1).

20002001121721 is an equidigital number, since it uses as much as digits as its factorization.

20002001121721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112, while the sum is 19.

Adding to 20002001121721 its reverse (12712110020002), we get a palindrome (32714111141723).

The spelling of 20002001121721 in words is "twenty trillion, two billion, one million, one hundred twenty-one thousand, seven hundred twenty-one".