18440947 has 8 divisors (see below), whose sum is σ = 21269600. Its totient is φ = 15660864.

The previous prime is 18440927. The next prime is 18440951. The reversal of 18440947 is 74904481.

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

It is a cyclic number.

It is not a de Polignac number, because 18440947 - 2¹⁵ = 18408179 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18440927) 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 7 ways as a sum of consecutive naturals, for example, 11322 + ... + 12847.

It is an arithmetic number, because the mean of its divisors is an integer number (2658700).

Almost surely, 2^18440947 is an apocalyptic number.

18440947 is a deficient number, since it is larger than the sum of its proper divisors (2828653).

18440947 is a wasteful number, since it uses less digits than its factorization.

18440947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24285.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 18440947 is about 4294.2923747691. The cubic root of 18440947 is about 264.1969136563.

The spelling of 18440947 in words is "eighteen million, four hundred forty thousand, nine hundred forty-seven".