18081247 has 4 divisors (see below), whose sum is σ = 18247240. Its totient is φ = 17915256.

The previous prime is 18081241. The next prime is 18081253. The reversal of 18081247 is 74218081.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (18081241) and next prime (18081253).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18081247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18081241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82833 + ... + 83050.

It is an arithmetic number, because the mean of its divisors is an integer number (4561810).

Almost surely, 2^18081247 is an apocalyptic number.

18081247 is a deficient number, since it is larger than the sum of its proper divisors (165993).

18081247 is a wasteful number, since it uses less digits than its factorization.

18081247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165992.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 18081247 is about 4252.2049574309. The cubic root of 18081247 is about 262.4678575912.

The spelling of 18081247 in words is "eighteen million, eighty-one thousand, two hundred forty-seven".