1191591023 has 16 divisors (see below), whose sum is σ = 1435200000. Its totient is φ = 966455712.

The previous prime is 1191590999. The next prime is 1191591029. The reversal of 1191591023 is 3201951911.

It is a cyclic number.

It is not a de Polignac number, because 1191591023 - 2⁸ = 1191590767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191591029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117353 + ... + 127101.

It is an arithmetic number, because the mean of its divisors is an integer number (89700000).

Almost surely, 2^1191591023 is an apocalyptic number.

1191591023 is a deficient number, since it is larger than the sum of its proper divisors (243608977).

1191591023 is an equidigital number, since it uses as much as digits as its factorization.

1191591023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10694.

The product of its (nonzero) digits is 2430, while the sum is 32.

The square root of 1191591023 is about 34519.4296447667. The cubic root of 1191591023 is about 1060.1705620281.

The spelling of 1191591023 in words is "one billion, one hundred ninety-one million, five hundred ninety-one thousand, twenty-three".