1191191282821 has 2 divisors, whose sum is σ = 1191191282822. Its totient is φ = 1191191282820.

The previous prime is 1191191282789. The next prime is 1191191282839. The reversal of 1191191282821 is 1282821911911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1022553753796 + 168637529025 = 1011214^2 + 410655^2 .

It is a cyclic number.

It is not a de Polignac number, because 1191191282821 - 2⁵ = 1191191282789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1191191232821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595595641410 + 595595641411.

It is an arithmetic number, because the mean of its divisors is an integer number (595595641411).

Almost surely, 2^{1191191282821} is an apocalyptic number.

It is an amenable number.

1191191282821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191191282821 is an equidigital number, since it uses as much as digits as its factorization.

1191191282821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 46.

The spelling of 1191191282821 in words is "one trillion, one hundred ninety-one billion, one hundred ninety-one million, two hundred eighty-two thousand, eight hundred twenty-one".