20110221009961 has 2 divisors, whose sum is σ = 20110221009962. Its totient is φ = 20110221009960.

The previous prime is 20110221009959. The next prime is 20110221010067. The reversal of 20110221009961 is 16990012201102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16570720611225 + 3539500398736 = 4070715^2 + 1881356^2 .

It is a cyclic number.

It is not a de Polignac number, because 20110221009961 - 2¹ = 20110221009959 is a prime.

It is a super-2 number, since 2×20110221009961² (a number of 27 digits) contains 22 as substring.

Together with 20110221009959, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20110221009911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055110504980 + 10055110504981.

It is an arithmetic number, because the mean of its divisors is an integer number (10055110504981).

Almost surely, 2^{20110221009961} is an apocalyptic number.

It is an amenable number.

20110221009961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110221009961 is an equidigital number, since it uses as much as digits as its factorization.

20110221009961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 34.

The spelling of 20110221009961 in words is "twenty trillion, one hundred ten billion, two hundred twenty-one million, nine thousand, nine hundred sixty-one".