18186457 has 2 divisors, whose sum is σ = 18186458. Its totient is φ = 18186456.

The previous prime is 18186431. The next prime is 18186461. The reversal of 18186457 is 75468181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18181696 + 4761 = 4264^2 + 69^2 .

It is an emirp because it is prime and its reverse (75468181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18186457 - 2¹¹ = 18184409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18186757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9093228 + 9093229.

It is an arithmetic number, because the mean of its divisors is an integer number (9093229).

Almost surely, 2^18186457 is an apocalyptic number.

It is an amenable number.

18186457 is a deficient number, since it is larger than the sum of its proper divisors (1).

18186457 is an equidigital number, since it uses as much as digits as its factorization.

18186457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 40.

The square root of 18186457 is about 4264.5582420692. The cubic root of 18186457 is about 262.9759504194.

The spelling of 18186457 in words is "eighteen million, one hundred eighty-six thousand, four hundred fifty-seven".