21220111031177 has 2 divisors, whose sum is σ = 21220111031178. Its totient is φ = 21220111031176.

The previous prime is 21220111031107. The next prime is 21220111031227. The reversal of 21220111031177 is 77113011102212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20435001619081 + 785109412096 = 4520509^2 + 886064^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220111031177 - 2²⁰ = 21220109982601 is a prime.

It is a super-2 number, since 2×21220111031177² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21220111031107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610055515588 + 10610055515589.

It is an arithmetic number, because the mean of its divisors is an integer number (10610055515589).

Almost surely, 2^{21220111031177} is an apocalyptic number.

It is an amenable number.

21220111031177 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220111031177 is an equidigital number, since it uses as much as digits as its factorization.

21220111031177 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1176, while the sum is 29.

Adding to 21220111031177 its reverse (77113011102212), we get a palindrome (98333122133389).

The spelling of 21220111031177 in words is "twenty-one trillion, two hundred twenty billion, one hundred eleven million, thirty-one thousand, one hundred seventy-seven".