18840133 has 4 divisors (see below), whose sum is σ = 20289388. Its totient is φ = 17390880.

The previous prime is 18840121. The next prime is 18840137. The reversal of 18840133 is 33104881.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1258884 + 17581249 = 1122^2 + 4193^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18840133 is a prime.

It is a super-2 number, since 2×18840133² = 709901222915378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18840137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 724608 + ... + 724633.

It is an arithmetic number, because the mean of its divisors is an integer number (5072347).

Almost surely, 2^18840133 is an apocalyptic number.

18840133 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18840133 is a deficient number, since it is larger than the sum of its proper divisors (1449255).

18840133 is a wasteful number, since it uses less digits than its factorization.

18840133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1449254.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 18840133 is about 4340.5222036064. The cubic root of 18840133 is about 266.0896535754.

The spelling of 18840133 in words is "eighteen million, eight hundred forty thousand, one hundred thirty-three".