1191191623 has 2 divisors, whose sum is σ = 1191191624. Its totient is φ = 1191191622.

The previous prime is 1191191569. The next prime is 1191191629. The reversal of 1191191623 is 3261911911.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1191191623 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1191191629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 595595811 + 595595812.

It is an arithmetic number, because the mean of its divisors is an integer number (595595812).

Almost surely, 2^1191191623 is an apocalyptic number.

1191191623 is a deficient number, since it is larger than the sum of its proper divisors (1).

1191191623 is an equidigital number, since it uses as much as digits as its factorization.

1191191623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2916, while the sum is 34.

The square root of 1191191623 is about 34513.6440121874. The cubic root of 1191191623 is about 1060.0520987209.

The spelling of 1191191623 in words is "one billion, one hundred ninety-one million, one hundred ninety-one thousand, six hundred twenty-three".