1211210012261 has 2 divisors, whose sum is σ = 1211210012262. Its totient is φ = 1211210012260.

The previous prime is 1211210012219. The next prime is 1211210012267. The reversal of 1211210012261 is 1622100121121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1001212367236 + 209997645025 = 1000606^2 + 458255^2 .

It is an emirp because it is prime and its reverse (1622100121121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211210012261 - 2¹⁸ = 1211209750117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211210012267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605605006130 + 605605006131.

It is an arithmetic number, because the mean of its divisors is an integer number (605605006131).

Almost surely, 2^{1211210012261} is an apocalyptic number.

It is an amenable number.

1211210012261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211210012261 is an equidigital number, since it uses as much as digits as its factorization.

1211210012261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 1211210012261 its reverse (1622100121121), we get a palindrome (2833310133382).

The spelling of 1211210012261 in words is "one trillion, two hundred eleven billion, two hundred ten million, twelve thousand, two hundred sixty-one".