18478947 has 16 divisors (see below), whose sum is σ = 25438112. Its totient is φ = 11923200.

The previous prime is 18478939. The next prime is 18478951. The reversal of 18478947 is 74987481.

It is not a de Polignac number, because 18478947 - 2³ = 18478939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18478896 and 18478905.

It is not an unprimeable number, because it can be changed into a prime (18478147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30447 + ... + 31047.

It is an arithmetic number, because the mean of its divisors is an integer number (1589882).

Almost surely, 2^18478947 is an apocalyptic number.

18478947 is a deficient number, since it is larger than the sum of its proper divisors (6959165).

18478947 is a wasteful number, since it uses less digits than its factorization.

18478947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918.

The product of its digits is 451584, while the sum is 48.

The square root of 18478947 is about 4298.7145753120. The cubic root of 18478947 is about 264.3782599959.

The spelling of 18478947 in words is "eighteen million, four hundred seventy-eight thousand, nine hundred forty-seven".