2178461 has 2 divisors, whose sum is σ = 2178462. Its totient is φ = 2178460.

The previous prime is 2178443. The next prime is 2178467. The reversal of 2178461 is 1648712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1943236 + 235225 = 1394^2 + 485^2 .

It is a cyclic number.

It is not a de Polignac number, because 2178461 - 2¹⁰ = 2177437 is a prime.

It is a Sophie Germain 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 (2178467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1089230 + 1089231.

It is an arithmetic number, because the mean of its divisors is an integer number (1089231).

2^2178461 is an apocalyptic number.

It is an amenable number.

2178461 is a deficient number, since it is larger than the sum of its proper divisors (1).

2178461 is an equidigital number, since it uses as much as digits as its factorization.

2178461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 29.

The square root of 2178461 is about 1475.9610428463. The cubic root of 2178461 is about 129.6333058801.

The spelling of 2178461 in words is "two million, one hundred seventy-eight thousand, four hundred sixty-one".