18423649 has 2 divisors, whose sum is σ = 18423650. Its totient is φ = 18423648.

The previous prime is 18423611. The next prime is 18423653. The reversal of 18423649 is 94632481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9809424 + 8614225 = 3132^2 + 2935^2 .

It is a cyclic number.

It is not a de Polignac number, because 18423649 - 2⁹ = 18423137 is a prime.

It is not a weakly prime, because it can be changed into another prime (18423659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9211824 + 9211825.

It is an arithmetic number, because the mean of its divisors is an integer number (9211825).

Almost surely, 2^18423649 is an apocalyptic number.

It is an amenable number.

18423649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18423649 is an equidigital number, since it uses as much as digits as its factorization.

18423649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 37.

The square root of 18423649 is about 4292.2778335052. The cubic root of 18423649 is about 264.1142803747.

The spelling of 18423649 in words is "eighteen million, four hundred twenty-three thousand, six hundred forty-nine".