18081601 has 2 divisors, whose sum is σ = 18081602. Its totient is φ = 18081600.

The previous prime is 18081593. The next prime is 18081607. The reversal of 18081601 is 10618081.

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., 16008001 + 2073600 = 4001^2 + 1440^2 .

It is a cyclic number.

It is not a de Polignac number, because 18081601 - 2³ = 18081593 is a prime.

It is not a weakly prime, because it can be changed into another prime (18081607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9040800 + 9040801.

It is an arithmetic number, because the mean of its divisors is an integer number (9040801).

Almost surely, 2^18081601 is an apocalyptic number.

It is an amenable number.

18081601 is a deficient number, since it is larger than the sum of its proper divisors (1).

18081601 is an equidigital number, since it uses as much as digits as its factorization.

18081601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 25.

The square root of 18081601 is about 4252.2465826901. The cubic root of 18081601 is about 262.4695704712.

Adding to 18081601 its reverse (10618081), we get a palindrome (28699682).

The spelling of 18081601 in words is "eighteen million, eighty-one thousand, six hundred one".