18891874 has 4 divisors (see below), whose sum is σ = 28337814. Its totient is φ = 9445936.

The previous prime is 18891869. The next prime is 18891877. The reversal of 18891874 is 47819881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 47819881 = 431 ⋅110951.

It can be written as a sum of positive squares in only one way, i.e., 16769025 + 2122849 = 4095^2 + 1457^2 .

It is not an unprimeable number, because it can be changed into a prime (18891877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4722967 + ... + 4722970.

Almost surely, 2^18891874 is an apocalyptic number.

18891874 is a deficient number, since it is larger than the sum of its proper divisors (9445940).

18891874 is an equidigital number, since it uses as much as digits as its factorization.

18891874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9445939.

The product of its digits is 129024, while the sum is 46.

The square root of 18891874 is about 4346.4783445912. The cubic root of 18891874 is about 266.3330198762. Note that the first 3 decimals are identical.

The spelling of 18891874 in words is "eighteen million, eight hundred ninety-one thousand, eight hundred seventy-four".