18891144 has 40 divisors (see below), whose sum is σ = 52914510. Its totient is φ = 6296832.

The previous prime is 18891143. The next prime is 18891193. The reversal of 18891144 is 44119881.

It can be written as a sum of positive squares in only one way, i.e., 18818244 + 72900 = 4338^2 + 270^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 18891099 and 18891108.

It is not an unprimeable number, because it can be changed into a prime (18891143) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 13929 + ... + 15224.

Almost surely, 2^18891144 is an apocalyptic number.

It is an amenable number.

18891144 is an abundant number, since it is smaller than the sum of its proper divisors (34023366).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18891144 is a wasteful number, since it uses less digits than its factorization.

18891144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29171 (or 29158 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 18891144 is about 4346.3943677490. The cubic root of 18891144 is about 266.3295893782.

The spelling of 18891144 in words is "eighteen million, eight hundred ninety-one thousand, one hundred forty-four".