21110220123137 has 2 divisors, whose sum is σ = 21110220123138. Its totient is φ = 21110220123136.

The previous prime is 21110220123103. The next prime is 21110220123169. The reversal of 21110220123137 is 73132102201112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12065230038016 + 9044990085121 = 3473504^2 + 3007489^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110220123137 - 2¹⁶ = 21110220057601 is a prime.

It is not a weakly prime, because it can be changed into another prime (21110220123037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555110061568 + 10555110061569.

It is an arithmetic number, because the mean of its divisors is an integer number (10555110061569).

Almost surely, 2^{21110220123137} is an apocalyptic number.

It is an amenable number.

21110220123137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110220123137 is an equidigital number, since it uses as much as digits as its factorization.

21110220123137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 26.

Adding to 21110220123137 its reverse (73132102201112), we get a palindrome (94242322324249).

The spelling of 21110220123137 in words is "twenty-one trillion, one hundred ten billion, two hundred twenty million, one hundred twenty-three thousand, one hundred thirty-seven".