18229947 has 4 divisors (see below), whose sum is σ = 24306600. Its totient is φ = 12153296.

The previous prime is 18229943. The next prime is 18229957. The reversal of 18229947 is 74992281.

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 18229947 - 2² = 18229943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18229899 and 18229908.

It is not an unprimeable number, because it can be changed into a prime (18229943) 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, 3038322 + ... + 3038327.

It is an arithmetic number, because the mean of its divisors is an integer number (6076650).

Almost surely, 2^18229947 is an apocalyptic number.

18229947 is a deficient number, since it is larger than the sum of its proper divisors (6076653).

18229947 is an equidigital number, since it uses as much as digits as its factorization.

18229947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6076652.

The product of its digits is 72576, while the sum is 42.

The square root of 18229947 is about 4269.6542014547. The cubic root of 18229947 is about 263.1854051752.

The spelling of 18229947 in words is "eighteen million, two hundred twenty-nine thousand, nine hundred forty-seven".