21062121161 has 2 divisors, whose sum is σ = 21062121162. Its totient is φ = 21062121160.

The previous prime is 21062121061. The next prime is 21062121169. The reversal of 21062121161 is 16112126012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18606324025 + 2455797136 = 136405^2 + 49556^2 .

It is a cyclic number.

It is not a de Polignac number, because 21062121161 - 2¹⁰ = 21062120137 is a prime.

It is a super-2 number, since 2×21062121161² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21062121169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10531060580 + 10531060581.

It is an arithmetic number, because the mean of its divisors is an integer number (10531060581).

Almost surely, 2^21062121161 is an apocalyptic number.

It is an amenable number.

21062121161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21062121161 is an equidigital number, since it uses as much as digits as its factorization.

21062121161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

Adding to 21062121161 its reverse (16112126012), we get a palindrome (37174247173).

The spelling of 21062121161 in words is "twenty-one billion, sixty-two million, one hundred twenty-one thousand, one hundred sixty-one".