181801331401 has 2 divisors, whose sum is σ = 181801331402. Its totient is φ = 181801331400.

The previous prime is 181801331363. The next prime is 181801331417. The reversal of 181801331401 is 104133108181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150215155776 + 31586175625 = 387576^2 + 177725^2 .

It is an emirp because it is prime and its reverse (104133108181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181801331401 - 2²⁵ = 181767776969 is a prime.

It is not a weakly prime, because it can be changed into another prime (181801331461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90900665700 + 90900665701.

It is an arithmetic number, because the mean of its divisors is an integer number (90900665701).

Almost surely, 2^181801331401 is an apocalyptic number.

It is an amenable number.

181801331401 is a deficient number, since it is larger than the sum of its proper divisors (1).

181801331401 is an equidigital number, since it uses as much as digits as its factorization.

181801331401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 31.

Adding to 181801331401 its reverse (104133108181), we get a palindrome (285934439582).

The spelling of 181801331401 in words is "one hundred eighty-one billion, eight hundred one million, three hundred thirty-one thousand, four hundred one".