181861429 has 2 divisors, whose sum is σ = 181861430. Its totient is φ = 181861428.

The previous prime is 181861417. The next prime is 181861447. The reversal of 181861429 is 924168181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159516900 + 22344529 = 12630^2 + 4727^2 .

It is an emirp because it is prime and its reverse (924168181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181861429 - 2¹⁹ = 181337141 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 181861391 and 181861400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181861499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90930714 + 90930715.

It is an arithmetic number, because the mean of its divisors is an integer number (90930715).

Almost surely, 2^181861429 is an apocalyptic number.

It is an amenable number.

181861429 is a deficient number, since it is larger than the sum of its proper divisors (1).

181861429 is an equidigital number, since it uses as much as digits as its factorization.

181861429 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 40.

The square root of 181861429 is about 13485.6008023373. The cubic root of 181861429 is about 566.5612484792.

The spelling of 181861429 in words is "one hundred eighty-one million, eight hundred sixty-one thousand, four hundred twenty-nine".