18400223 has 4 divisors (see below), whose sum is σ = 18701928. Its totient is φ = 18098520.

The previous prime is 18400177. The next prime is 18400237. The reversal of 18400223 is 32200481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32200481 = 1657 ⋅19433.

It is a cyclic number.

It is not a de Polignac number, because 18400223 - 2¹² = 18396127 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18400195 and 18400204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18400423) 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, 150761 + ... + 150882.

It is an arithmetic number, because the mean of its divisors is an integer number (4675482).

Almost surely, 2^18400223 is an apocalyptic number.

18400223 is a deficient number, since it is larger than the sum of its proper divisors (301705).

18400223 is an equidigital number, since it uses as much as digits as its factorization.

18400223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301704.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 18400223 is about 4289.5481113982. The cubic root of 18400223 is about 264.0022908816.

The spelling of 18400223 in words is "eighteen million, four hundred thousand, two hundred twenty-three".