18378461 has 2 divisors, whose sum is σ = 18378462. Its totient is φ = 18378460.

The previous prime is 18378401. The next prime is 18378473. The reversal of 18378461 is 16487381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13734436 + 4644025 = 3706^2 + 2155^2 .

It is a cyclic number.

It is not a de Polignac number, because 18378461 - 2¹⁴ = 18362077 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18378401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9189230 + 9189231.

It is an arithmetic number, because the mean of its divisors is an integer number (9189231).

Almost surely, 2^18378461 is an apocalyptic number.

It is an amenable number.

18378461 is a deficient number, since it is larger than the sum of its proper divisors (1).

18378461 is an equidigital number, since it uses as much as digits as its factorization.

18378461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32256, while the sum is 38.

The square root of 18378461 is about 4287.0107301009. The cubic root of 18378461 is about 263.8981710510.

The spelling of 18378461 in words is "eighteen million, three hundred seventy-eight thousand, four hundred sixty-one".