18140447 has 4 divisors (see below), whose sum is σ = 19535880. Its totient is φ = 16745016.

The previous prime is 18140431. The next prime is 18140461. The reversal of 18140447 is 74404181.

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 18140447 - 2⁴ = 18140431 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18140467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 697697 + ... + 697722.

It is an arithmetic number, because the mean of its divisors is an integer number (4883970).

Almost surely, 2^18140447 is an apocalyptic number.

18140447 is a deficient number, since it is larger than the sum of its proper divisors (1395433).

18140447 is a wasteful number, since it uses less digits than its factorization.

18140447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395432.

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 18140447 is about 4259.1603632641. The cubic root of 18140447 is about 262.7539951224.

The spelling of 18140447 in words is "eighteen million, one hundred forty thousand, four hundred forty-seven".