181661283929 has 2 divisors, whose sum is σ = 181661283930. Its totient is φ = 181661283928.

The previous prime is 181661283919. The next prime is 181661283941. The reversal of 181661283929 is 929382166181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 178631331904 + 3029952025 = 422648^2 + 55045^2 .

It is a cyclic number.

It is not a de Polignac number, because 181661283929 - 2⁴ = 181661283913 is a prime.

It is not a weakly prime, because it can be changed into another prime (181661283919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90830641964 + 90830641965.

It is an arithmetic number, because the mean of its divisors is an integer number (90830641965).

Almost surely, 2^181661283929 is an apocalyptic number.

It is an amenable number.

181661283929 is a deficient number, since it is larger than the sum of its proper divisors (1).

181661283929 is an equidigital number, since it uses as much as digits as its factorization.

181661283929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 56.

The spelling of 181661283929 in words is "one hundred eighty-one billion, six hundred sixty-one million, two hundred eighty-three thousand, nine hundred twenty-nine".