18456409 has 2 divisors, whose sum is σ = 18456410. Its totient is φ = 18456408.

The previous prime is 18456337. The next prime is 18456421. The reversal of 18456409 is 90465481.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10208025 + 8248384 = 3195^2 + 2872^2 .

It is a cyclic number.

It is not a de Polignac number, because 18456409 - 2¹¹ = 18454361 is a prime.

It is not a weakly prime, because it can be changed into another prime (18456469) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9228204 + 9228205.

It is an arithmetic number, because the mean of its divisors is an integer number (9228205).

Almost surely, 2^18456409 is an apocalyptic number.

It is an amenable number.

18456409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18456409 is an equidigital number, since it uses as much as digits as its factorization.

18456409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 37.

The square root of 18456409 is about 4296.0922941669. The cubic root of 18456409 is about 264.2707325606.

The spelling of 18456409 in words is "eighteen million, four hundred fifty-six thousand, four hundred nine".