181667201 has 2 divisors, whose sum is σ = 181667202. Its totient is φ = 181667200.

The previous prime is 181667191. The next prime is 181667237. The reversal of 181667201 is 102766181.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 106584976 + 75082225 = 10324^2 + 8665^2 .

It is a cyclic number.

It is not a de Polignac number, because 181667201 - 2¹⁸ = 181405057 is a prime.

It is not a weakly prime, because it can be changed into another prime (181667401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90833600 + 90833601.

It is an arithmetic number, because the mean of its divisors is an integer number (90833601).

Almost surely, 2^181667201 is an apocalyptic number.

It is an amenable number.

181667201 is a deficient number, since it is larger than the sum of its proper divisors (1).

181667201 is an equidigital number, since it uses as much as digits as its factorization.

181667201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 181667201 is about 13478.3975679604. The cubic root of 181667201 is about 566.3594808349.

The spelling of 181667201 in words is "one hundred eighty-one million, six hundred sixty-seven thousand, two hundred one".