10211020201721 has 2 divisors, whose sum is σ = 10211020201722. Its totient is φ = 10211020201720.

The previous prime is 10211020201717. The next prime is 10211020201763. The reversal of 10211020201721 is 12710202011201.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7456203666025 + 2754816535696 = 2730605^2 + 1659764^2 .

It is a cyclic number.

It is not a de Polignac number, because 10211020201721 - 2² = 10211020201717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 10211020201693 and 10211020201702.

It is not a weakly prime, because it can be changed into another prime (10211020200721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5105510100860 + 5105510100861.

It is an arithmetic number, because the mean of its divisors is an integer number (5105510100861).

Almost surely, 2^{10211020201721} is an apocalyptic number.

It is an amenable number.

10211020201721 is a deficient number, since it is larger than the sum of its proper divisors (1).

10211020201721 is an equidigital number, since it uses as much as digits as its factorization.

10211020201721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 20.

Adding to 10211020201721 its reverse (12710202011201), we get a palindrome (22921222212922).

The spelling of 10211020201721 in words is "ten trillion, two hundred eleven billion, twenty million, two hundred one thousand, seven hundred twenty-one".