21221201221177 has 2 divisors, whose sum is σ = 21221201221178. Its totient is φ = 21221201221176.

The previous prime is 21221201221117. The next prime is 21221201221183. The reversal of 21221201221177 is 77112210212212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14163698913961 + 7057502307216 = 3763469^2 + 2656596^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221201221177 - 2⁷ = 21221201221049 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221201221117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610600610588 + 10610600610589.

It is an arithmetic number, because the mean of its divisors is an integer number (10610600610589).

Almost surely, 2^{21221201221177} is an apocalyptic number.

It is an amenable number.

21221201221177 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221201221177 is an equidigital number, since it uses as much as digits as its factorization.

21221201221177 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3136, while the sum is 31.

Adding to 21221201221177 its reverse (77112210212212), we get a palindrome (98333411433389).

The spelling of 21221201221177 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred one million, two hundred twenty-one thousand, one hundred seventy-seven".