1191942081121 has 9 divisors (see below), whose sum is σ = 1310164413649. Its totient is φ = 1083572792500.

The previous prime is 1191942081107. The next prime is 1191942081151. The reversal of 1191942081121 is 1211802491911.

The square root of 1191942081121 is 1091761.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1191942081121 - 2¹⁷ = 1191941950049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1191942081151) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11959746 + ... + 12058996.

Almost surely, 2^{1191942081121} is an apocalyptic number.

1191942081121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1191942081121 is the 1091761-st square number.

1191942081121 is the 545881-st centered octagonal number.

It is an amenable number.

1191942081121 is a deficient number, since it is larger than the sum of its proper divisors (118222332528).

1191942081121 is an frugal number, since it uses more digits than its factorization.

1191942081121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198524 (or 99262 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 40.

The spelling of 1191942081121 in words is "one trillion, one hundred ninety-one billion, nine hundred forty-two million, eighty-one thousand, one hundred twenty-one".