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18125381 is a prime number
BaseRepresentation
bin100010100100…
…1001001000101
31021002212100102
41011021021011
514120003011
61444253445
7310030451
oct105111105
937085312
1018125381
11a25a95a
1260a1285
1339a80a1
14259b661
1518d073b
hex1149245

18125381 has 2 divisors, whose sum is σ = 18125382. Its totient is φ = 18125380.

The previous prime is 18125363. The next prime is 18125407. The reversal of 18125381 is 18352181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17297281 + 828100 = 4159^2 + 910^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-18125381 is a prime.

It is a super-2 number, since 2×181253812 = 657058872790322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18125351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9062690 + 9062691.

It is an arithmetic number, because the mean of its divisors is an integer number (9062691).

Almost surely, 218125381 is an apocalyptic number.

It is an amenable number.

18125381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18125381 is an equidigital number, since it uses as much as digits as its factorization.

18125381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1920, while the sum is 29.

The square root of 18125381 is about 4257.3913374272. The cubic root of 18125381 is about 262.6812341791.

The spelling of 18125381 in words is "eighteen million, one hundred twenty-five thousand, three hundred eighty-one".