18024781 has 2 divisors, whose sum is σ = 18024782. Its totient is φ = 18024780.

The previous prime is 18024779. The next prime is 18024793. The reversal of 18024781 is 18742081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14891881 + 3132900 = 3859^2 + 1770^2 .

It is a cyclic number.

It is not a de Polignac number, because 18024781 - 2¹ = 18024779 is a prime.

It is a super-2 number, since 2×18024781² = 649785460195922, which contains 22 as substring.

Together with 18024779, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18024761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9012390 + 9012391.

It is an arithmetic number, because the mean of its divisors is an integer number (9012391).

Almost surely, 2^18024781 is an apocalyptic number.

It is an amenable number.

18024781 is a deficient number, since it is larger than the sum of its proper divisors (1).

18024781 is an equidigital number, since it uses as much as digits as its factorization.

18024781 is an evil number, because the sum of its binary digits is even.

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

The square root of 18024781 is about 4245.5601514994. The cubic root of 18024781 is about 262.1943520352.

The spelling of 18024781 in words is "eighteen million, twenty-four thousand, seven hundred eighty-one".