191923643 has 4 divisors (see below), whose sum is σ = 194552808. Its totient is φ = 189294480.

The previous prime is 191923631. The next prime is 191923651. The reversal of 191923643 is 346329191.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346329191 = 13 ⋅26640707.

It is a cyclic number.

It is not a de Polignac number, because 191923643 - 2¹² = 191919547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191923597 and 191923606.

It is not an unprimeable number, because it can be changed into a prime (191923243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1314473 + ... + 1314618.

It is an arithmetic number, because the mean of its divisors is an integer number (48638202).

Almost surely, 2^191923643 is an apocalyptic number.

191923643 is a deficient number, since it is larger than the sum of its proper divisors (2629165).

191923643 is an equidigital number, since it uses as much as digits as its factorization.

191923643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2629164.

The product of its digits is 34992, while the sum is 38.

The square root of 191923643 is about 13853.6508906497. The cubic root of 191923643 is about 576.8233416977.

The spelling of 191923643 in words is "one hundred ninety-one million, nine hundred twenty-three thousand, six hundred forty-three".