18161244 has 18 divisors (see below), whose sum is σ = 45907680. Its totient is φ = 6053736.

The previous prime is 18161197. The next prime is 18161261. The reversal of 18161244 is 44216181.

It is a happy number.

18161244 is a `hidden beast` number, since 1 + 8 + 1 + 612 + 44 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 252204 + ... + 252275.

Almost surely, 2^18161244 is an apocalyptic number.

It is an amenable number.

18161244 is an abundant number, since it is smaller than the sum of its proper divisors (27746436).

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

18161244 is a wasteful number, since it uses less digits than its factorization.

18161244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504489 (or 504484 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 18161244 is about 4261.6011075651. The cubic root of 18161244 is about 262.8543676568.

It can be divided in two parts, 181 and 61244, that added together give a triangular number (61425 = T₃₅₀).

The spelling of 18161244 in words is "eighteen million, one hundred sixty-one thousand, two hundred forty-four".