18646457 has 2 divisors, whose sum is σ = 18646458. Its totient is φ = 18646456.

The previous prime is 18646427. The next prime is 18646471. The reversal of 18646457 is 75464681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17732521 + 913936 = 4211^2 + 956^2 .

It is an emirp because it is prime and its reverse (75464681) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18646457 is a prime.

It is not a weakly prime, because it can be changed into another prime (18646417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9323228 + 9323229.

It is an arithmetic number, because the mean of its divisors is an integer number (9323229).

Almost surely, 2^18646457 is an apocalyptic number.

It is an amenable number.

18646457 is a deficient number, since it is larger than the sum of its proper divisors (1).

18646457 is an equidigital number, since it uses as much as digits as its factorization.

18646457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 41.

The square root of 18646457 is about 4318.1543511088. The cubic root of 18646457 is about 265.1747133143.

The spelling of 18646457 in words is "eighteen million, six hundred forty-six thousand, four hundred fifty-seven".