181402856321 has 2 divisors, whose sum is σ = 181402856322. Its totient is φ = 181402856320.

The previous prime is 181402856213. The next prime is 181402856329. The reversal of 181402856321 is 123658204181.

Together with previous prime (181402856213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180825655696 + 577200625 = 425236^2 + 24025^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181402856321 is a prime.

It is not a weakly prime, because it can be changed into another prime (181402856329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90701428160 + 90701428161.

It is an arithmetic number, because the mean of its divisors is an integer number (90701428161).

Almost surely, 2^181402856321 is an apocalyptic number.

It is an amenable number.

181402856321 is a deficient number, since it is larger than the sum of its proper divisors (1).

181402856321 is an equidigital number, since it uses as much as digits as its factorization.

181402856321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 181402856321 in words is "one hundred eighty-one billion, four hundred two million, eight hundred fifty-six thousand, three hundred twenty-one".