18400247 has 2 divisors, whose sum is σ = 18400248. Its totient is φ = 18400246.

The previous prime is 18400241. The next prime is 18400301. The reversal of 18400247 is 74200481.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18400247 - 2¹⁰ = 18399223 is a prime.

It is a super-2 number, since 2×18400247² = 677138179322018, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18400241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9200123 + 9200124.

It is an arithmetic number, because the mean of its divisors is an integer number (9200124).

Almost surely, 2^18400247 is an apocalyptic number.

18400247 is a deficient number, since it is larger than the sum of its proper divisors (1).

18400247 is an equidigital number, since it uses as much as digits as its factorization.

18400247 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 18400247 is about 4289.5509088948. The cubic root of 18400247 is about 264.0024056637.

The spelling of 18400247 in words is "eighteen million, four hundred thousand, two hundred forty-seven".