18033813 has 48 divisors (see below), whose sum is σ = 31901760. Its totient is φ = 10033632.

The previous prime is 18033811. The next prime is 18033823. The reversal of 18033813 is 31833081.

It is not a de Polignac number, because 18033813 - 2¹ = 18033811 is a prime.

It is a super-2 number, since 2×18033813² = 650436822637938, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18033811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 56731 + ... + 57047.

It is an arithmetic number, because the mean of its divisors is an integer number (664620).

Almost surely, 2^18033813 is an apocalyptic number.

It is an amenable number.

18033813 is a deficient number, since it is larger than the sum of its proper divisors (13867947).

18033813 is a wasteful number, since it uses less digits than its factorization.

18033813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383 (or 370 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 18033813 is about 4246.6237177315. The cubic root of 18033813 is about 262.2381388630.

Adding to 18033813 its reverse (31833081), we get a palindrome (49866894).

The spelling of 18033813 in words is "eighteen million, thirty-three thousand, eight hundred thirteen".