101221201261 has 2 divisors, whose sum is σ = 101221201262. Its totient is φ = 101221201260.

The previous prime is 101221201201. The next prime is 101221201373. The reversal of 101221201261 is 162102122101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82641875625 + 18579325636 = 287475^2 + 136306^2 .

It is a cyclic number.

It is not a de Polignac number, because 101221201261 - 2⁹ = 101221200749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101221201201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50610600630 + 50610600631.

It is an arithmetic number, because the mean of its divisors is an integer number (50610600631).

Almost surely, 2^101221201261 is an apocalyptic number.

It is an amenable number.

101221201261 is a deficient number, since it is larger than the sum of its proper divisors (1).

101221201261 is an equidigital number, since it uses as much as digits as its factorization.

101221201261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 101221201261 its reverse (162102122101), we get a palindrome (263323323362).

The spelling of 101221201261 in words is "one hundred one billion, two hundred twenty-one million, two hundred one thousand, two hundred sixty-one".