181135846421 has 2 divisors, whose sum is σ = 181135846422. Its totient is φ = 181135846420.

The previous prime is 181135846399. The next prime is 181135846439. The reversal of 181135846421 is 124648531181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111432454225 + 69703392196 = 333815^2 + 264014^2 .

It is a cyclic number.

It is not a de Polignac number, because 181135846421 - 2¹⁴ = 181135830037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181135846921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90567923210 + 90567923211.

It is an arithmetic number, because the mean of its divisors is an integer number (90567923211).

Almost surely, 2^181135846421 is an apocalyptic number.

It is an amenable number.

181135846421 is a deficient number, since it is larger than the sum of its proper divisors (1).

181135846421 is an equidigital number, since it uses as much as digits as its factorization.

181135846421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 184320, while the sum is 44.

The spelling of 181135846421 in words is "one hundred eighty-one billion, one hundred thirty-five million, eight hundred forty-six thousand, four hundred twenty-one".