2181461 has 2 divisors, whose sum is σ = 2181462. Its totient is φ = 2181460.

The previous prime is 2181449. The next prime is 2181463. The reversal of 2181461 is 1641812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2102500 + 78961 = 1450^2 + 281^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181461 - 2¹⁴ = 2165077 is a prime.

It is a Sophie Germain prime.

Together with 2181463, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2181463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1090730 + 1090731.

It is an arithmetic number, because the mean of its divisors is an integer number (1090731).

2^2181461 is an apocalyptic number.

It is an amenable number.

2181461 is a deficient number, since it is larger than the sum of its proper divisors (1).

2181461 is an equidigital number, since it uses as much as digits as its factorization.

2181461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 23.

The square root of 2181461 is about 1476.9769801862. The cubic root of 2181461 is about 129.6927854139.

The spelling of 2181461 in words is "two million, one hundred eighty-one thousand, four hundred sixty-one".