18840823 has 4 divisors (see below), whose sum is σ = 18930328. Its totient is φ = 18751320.

The previous prime is 18840817. The next prime is 18840847. The reversal of 18840823 is 32804881.

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

It is a cyclic number.

It is not a de Polignac number, because 18840823 - 2⁵ = 18840791 is a prime.

It is a super-2 number, since 2×18840823² = 709953222634658, 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 (18840803) 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, 44436 + ... + 44857.

It is an arithmetic number, because the mean of its divisors is an integer number (4732582).

Almost surely, 2^18840823 is an apocalyptic number.

18840823 is a deficient number, since it is larger than the sum of its proper divisors (89505).

18840823 is an equidigital number, since it uses as much as digits as its factorization.

18840823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89504.

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 18840823 is about 4340.6016864025. The cubic root of 18840823 is about 266.0929019534.

The spelling of 18840823 in words is "eighteen million, eight hundred forty thousand, eight hundred twenty-three".