18491147 has 2 divisors, whose sum is σ = 18491148. Its totient is φ = 18491146.

The previous prime is 18491111. The next prime is 18491173. The reversal of 18491147 is 74119481.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18491147 - 2⁸ = 18490891 is a prime.

It is a super-5 number, since 5×18491147⁵ (a number of 38 digits) contains 55555 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18491107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9245573 + 9245574.

It is an arithmetic number, because the mean of its divisors is an integer number (9245574).

Almost surely, 2^18491147 is an apocalyptic number.

18491147 is a deficient number, since it is larger than the sum of its proper divisors (1).

18491147 is an equidigital number, since it uses as much as digits as its factorization.

18491147 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 35.

The square root of 18491147 is about 4300.1333700247. The cubic root of 18491147 is about 264.4364289889.

The spelling of 18491147 in words is "eighteen million, four hundred ninety-one thousand, one hundred forty-seven".