1111212021961 has 2 divisors, whose sum is σ = 1111212021962. Its totient is φ = 1111212021960.

The previous prime is 1111212021949. The next prime is 1111212021967. The reversal of 1111212021961 is 1691202121111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 989937441936 + 121274580025 = 994956^2 + 348245^2 .

It is a cyclic number.

It is not a de Polignac number, because 1111212021961 - 2¹⁷ = 1111211890889 is a prime.

It is not a weakly prime, because it can be changed into another prime (1111212021967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555606010980 + 555606010981.

It is an arithmetic number, because the mean of its divisors is an integer number (555606010981).

Almost surely, 2^{1111212021961} is an apocalyptic number.

It is an amenable number.

1111212021961 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111212021961 is an equidigital number, since it uses as much as digits as its factorization.

1111212021961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 28.

The spelling of 1111212021961 in words is "one trillion, one hundred eleven billion, two hundred twelve million, twenty-one thousand, nine hundred sixty-one".