1991310023 has 8 divisors (see below), whose sum is σ = 2010096000. Its totient is φ = 1972609528.

The previous prime is 1991310007. The next prime is 1991310043. The reversal of 1991310023 is 3200131991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1991310023 - 2⁴ = 1991310007 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 (1991310043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25928 + ... + 68226.

It is an arithmetic number, because the mean of its divisors is an integer number (251262000).

Almost surely, 2^1991310023 is an apocalyptic number.

1991310023 is a deficient number, since it is larger than the sum of its proper divisors (18785977).

1991310023 is a wasteful number, since it uses less digits than its factorization.

1991310023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42741.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 1991310023 is about 44624.0968872200. The cubic root of 1991310023 is about 1258.0936197886.

The spelling of 1991310023 in words is "one billion, nine hundred ninety-one million, three hundred ten thousand, twenty-three".