1211211219961 has 2 divisors, whose sum is σ = 1211211219962. Its totient is φ = 1211211219960.

The previous prime is 1211211219913. The next prime is 1211211220027. The reversal of 1211211219961 is 1699121121121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1106409459600 + 104801760361 = 1051860^2 + 323731^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211211219961 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1211211219961.

It is not a weakly prime, because it can be changed into another prime (1211211249961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605605609980 + 605605609981.

It is an arithmetic number, because the mean of its divisors is an integer number (605605609981).

Almost surely, 2^{1211211219961} is an apocalyptic number.

It is an amenable number.

1211211219961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211211219961 is an equidigital number, since it uses as much as digits as its factorization.

1211211219961 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 37.

The spelling of 1211211219961 in words is "one trillion, two hundred eleven billion, two hundred eleven million, two hundred nineteen thousand, nine hundred sixty-one".