18051805 has 24 divisors (see below), whose sum is σ = 23344632. Its totient is φ = 13395456.

The previous prime is 18051793. The next prime is 18051811. The reversal of 18051805 is 50815081.

It can be written as a sum of positive squares in 4 ways, for example, as 2732409 + 15319396 = 1653^2 + 3914^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18051805 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 131697 + ... + 131833.

It is an arithmetic number, because the mean of its divisors is an integer number (972693).

Almost surely, 2^18051805 is an apocalyptic number.

It is an amenable number.

18051805 is a deficient number, since it is larger than the sum of its proper divisors (5292827).

18051805 is a wasteful number, since it uses less digits than its factorization.

18051805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 28.

The square root of 18051805 is about 4248.7415783971. The cubic root of 18051805 is about 262.3253199153.

Adding to 18051805 its reverse (50815081), we get a palindrome (68866886).

The spelling of 18051805 in words is "eighteen million, fifty-one thousand, eight hundred five".