181998101 has 2 divisors, whose sum is σ = 181998102. Its totient is φ = 181998100.

The previous prime is 181998083. The next prime is 181998143. The reversal of 181998101 is 101899181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 179533201 + 2464900 = 13399^2 + 1570^2 .

It is a cyclic number.

It is not a de Polignac number, because 181998101 - 2²² = 177803797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181998151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90999050 + 90999051.

It is an arithmetic number, because the mean of its divisors is an integer number (90999051).

Almost surely, 2^181998101 is an apocalyptic number.

It is an amenable number.

181998101 is a deficient number, since it is larger than the sum of its proper divisors (1).

181998101 is an equidigital number, since it uses as much as digits as its factorization.

181998101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 38.

The square root of 181998101 is about 13490.6671814258. The cubic root of 181998101 is about 566.7031397900.

The spelling of 181998101 in words is "one hundred eighty-one million, nine hundred ninety-eight thousand, one hundred one".