181398461 has 2 divisors, whose sum is σ = 181398462. Its totient is φ = 181398460.

The previous prime is 181398443. The next prime is 181398463. The reversal of 181398461 is 164893181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 180768025 + 630436 = 13445^2 + 794^2 .

It is a cyclic number.

It is not a de Polignac number, because 181398461 - 2¹⁴ = 181382077 is a prime.

It is a Sophie Germain prime.

Together with 181398463, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181398463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90699230 + 90699231.

It is an arithmetic number, because the mean of its divisors is an integer number (90699231).

Almost surely, 2^181398461 is an apocalyptic number.

It is an amenable number.

181398461 is a deficient number, since it is larger than the sum of its proper divisors (1).

181398461 is an equidigital number, since it uses as much as digits as its factorization.

181398461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 41.

The square root of 181398461 is about 13468.4245923567. The cubic root of 181398461 is about 566.0800714547.

The spelling of 181398461 in words is "one hundred eighty-one million, three hundred ninety-eight thousand, four hundred sixty-one".