18249947 has 2 divisors, whose sum is σ = 18249948. Its totient is φ = 18249946.

The previous prime is 18249941. The next prime is 18249997. The reversal of 18249947 is 74994281.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18249947 - 2⁸ = 18249691 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18249898 and 18249907.

It is not a weakly prime, because it can be changed into another prime (18249941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9124973 + 9124974.

It is an arithmetic number, because the mean of its divisors is an integer number (9124974).

Almost surely, 2^18249947 is an apocalyptic number.

18249947 is a deficient number, since it is larger than the sum of its proper divisors (1).

18249947 is an equidigital number, since it uses as much as digits as its factorization.

18249947 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 44.

The square root of 18249947 is about 4271.9956694735. The cubic root of 18249947 is about 263.2816165419.

The spelling of 18249947 in words is "eighteen million, two hundred forty-nine thousand, nine hundred forty-seven".