1191561359 has 2 divisors, whose sum is σ = 1191561360. Its totient is φ = 1191561358.

The previous prime is 1191561323. The next prime is 1191561379. The reversal of 1191561359 is 9531651911.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1191561359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1191561379) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595780679 + 595780680.

It is an arithmetic number, because the mean of its divisors is an integer number (595780680).

Almost surely, 2^1191561359 is an apocalyptic number.

1191561359 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191561359 is an equidigital number, since it uses as much as digits as its factorization.

1191561359 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36450, while the sum is 41.

The square root of 1191561359 is about 34518.9999710304. Note that the first 4 decimals coincide. The cubic root of 1191561359 is about 1060.1617645017.

The spelling of 1191561359 in words is "one billion, one hundred ninety-one million, five hundred sixty-one thousand, three hundred fifty-nine".