102011221721 has 2 divisors, whose sum is σ = 102011221722. Its totient is φ = 102011221720.

The previous prime is 102011221709. The next prime is 102011221727. The reversal of 102011221721 is 127122110201.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68520391696 + 33490830025 = 261764^2 + 183005^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102011221721 is a prime.

It is a super-2 number, since 2×102011221721² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 102011221693 and 102011221702.

It is not a weakly prime, because it can be changed into another prime (102011221727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51005610860 + 51005610861.

It is an arithmetic number, because the mean of its divisors is an integer number (51005610861).

Almost surely, 2^102011221721 is an apocalyptic number.

It is an amenable number.

102011221721 is a deficient number, since it is larger than the sum of its proper divisors (1).

102011221721 is an equidigital number, since it uses as much as digits as its factorization.

102011221721 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 20.

Adding to 102011221721 its reverse (127122110201), we get a palindrome (229133331922).

The spelling of 102011221721 in words is "one hundred two billion, eleven million, two hundred twenty-one thousand, seven hundred twenty-one".