181278481961 has 2 divisors, whose sum is σ = 181278481962. Its totient is φ = 181278481960.

The previous prime is 181278481933. The next prime is 181278481997. The reversal of 181278481961 is 169184872181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 149734945936 + 31543536025 = 386956^2 + 177605^2 .

It is a cyclic number.

It is not a de Polignac number, because 181278481961 - 2⁶ = 181278481897 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 181278481897 and 181278481906.

It is not a weakly prime, because it can be changed into another prime (181278481061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90639240980 + 90639240981.

It is an arithmetic number, because the mean of its divisors is an integer number (90639240981).

Almost surely, 2^181278481961 is an apocalyptic number.

It is an amenable number.

181278481961 is a deficient number, since it is larger than the sum of its proper divisors (1).

181278481961 is an equidigital number, since it uses as much as digits as its factorization.

181278481961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1548288, while the sum is 56.

The spelling of 181278481961 in words is "one hundred eighty-one billion, two hundred seventy-eight million, four hundred eighty-one thousand, nine hundred sixty-one".