21110022009961 has 2 divisors, whose sum is σ = 21110022009962. Its totient is φ = 21110022009960.

The previous prime is 21110022009917. The next prime is 21110022009997. The reversal of 21110022009961 is 16990022001112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10823152500736 + 10286869509225 = 3289856^2 + 3207315^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110022009961 - 2¹⁹ = 21110021485673 is a prime.

It is a super-2 number, since 2×21110022009961² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21110022000961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555011004980 + 10555011004981.

It is an arithmetic number, because the mean of its divisors is an integer number (10555011004981).

Almost surely, 2^{21110022009961} is an apocalyptic number.

It is an amenable number.

21110022009961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110022009961 is an equidigital number, since it uses as much as digits as its factorization.

21110022009961 is an evil number, because the sum of its binary digits is even.

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

The spelling of 21110022009961 in words is "twenty-one trillion, one hundred ten billion, twenty-two million, nine thousand, nine hundred sixty-one".