1891489423 has 4 divisors (see below), whose sum is σ = 1893744720. Its totient is φ = 1889234128.

The previous prime is 1891489421. The next prime is 1891489471. The reversal of 1891489423 is 3249841981.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1891489423 - 2¹ = 1891489421 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1891489421) 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 3 ways as a sum of consecutive naturals, for example, 1126390 + ... + 1128067.

It is an arithmetic number, because the mean of its divisors is an integer number (473436180).

Almost surely, 2^1891489423 is an apocalyptic number.

1891489423 is a deficient number, since it is larger than the sum of its proper divisors (2255297).

1891489423 is an equidigital number, since it uses as much as digits as its factorization.

1891489423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2255296.

The product of its digits is 497664, while the sum is 49.

The square root of 1891489423 is about 43491.2568569822. The cubic root of 1891489423 is about 1236.7102844067.

The spelling of 1891489423 in words is "one billion, eight hundred ninety-one million, four hundred eighty-nine thousand, four hundred twenty-three".