18871923 has 8 divisors (see below), whose sum is σ = 28757248. Its totient is φ = 10783944.

The previous prime is 18871913. The next prime is 18871927. The reversal of 18871923 is 32917881.

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

It is not a de Polignac number, because 18871923 - 2⁴ = 18871907 is a prime.

It is a super-2 number, since 2×18871923² = 712298955435858, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18871927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 449311 + ... + 449352.

It is an arithmetic number, because the mean of its divisors is an integer number (3594656).

Almost surely, 2^18871923 is an apocalyptic number.

18871923 is a deficient number, since it is larger than the sum of its proper divisors (9885325).

18871923 is an equidigital number, since it uses as much as digits as its factorization.

18871923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898673.

The product of its digits is 24192, while the sum is 39.

The square root of 18871923 is about 4344.1826619055. The cubic root of 18871923 is about 266.2392320801.

The spelling of 18871923 in words is "eighteen million, eight hundred seventy-one thousand, nine hundred twenty-three".