1191061331 has 2 divisors, whose sum is σ = 1191061332. Its totient is φ = 1191061330.

The previous prime is 1191061307. The next prime is 1191061337. The reversal of 1191061331 is 1331601911.

It is a strong prime.

It is an emirp because it is prime and its reverse (1331601911) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1191061331 - 2³⁰ = 117319507 is a prime.

It is a super-2 number, since 2×1191061331² = 2837254188406983122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1191061331.

It is not a weakly prime, because it can be changed into another prime (1191061337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595530665 + 595530666.

It is an arithmetic number, because the mean of its divisors is an integer number (595530666).

Almost surely, 2^1191061331 is an apocalyptic number.

1191061331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191061331 is an equidigital number, since it uses as much as digits as its factorization.

1191061331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 1191061331 is about 34511.7564171979. The cubic root of 1191061331 is about 1060.0134479723.

The spelling of 1191061331 in words is "one billion, one hundred ninety-one million, sixty-one thousand, three hundred thirty-one".