211312123261 has 2 divisors, whose sum is σ = 211312123262. Its totient is φ = 211312123260.

The previous prime is 211312123259. The next prime is 211312123271. The reversal of 211312123261 is 162321213112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208912984900 + 2399138361 = 457070^2 + 48981^2 .

It is a cyclic number.

It is not a de Polignac number, because 211312123261 - 2¹ = 211312123259 is a prime.

Together with 211312123259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211312123271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105656061630 + 105656061631.

It is an arithmetic number, because the mean of its divisors is an integer number (105656061631).

Almost surely, 2^211312123261 is an apocalyptic number.

It is an amenable number.

211312123261 is a deficient number, since it is larger than the sum of its proper divisors (1).

211312123261 is an equidigital number, since it uses as much as digits as its factorization.

211312123261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

Adding to 211312123261 its reverse (162321213112), we get a palindrome (373633336373).

The spelling of 211312123261 in words is "two hundred eleven billion, three hundred twelve million, one hundred twenty-three thousand, two hundred sixty-one".