31818223 has 4 divisors (see below), whose sum is σ = 33201648. Its totient is φ = 30434800.

The previous prime is 31818221. The next prime is 31818229. The reversal of 31818223 is 32281813.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32281813 = 89 ⋅362717.

It is a cyclic number.

It is not a de Polignac number, because 31818223 - 2¹ = 31818221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31818191 and 31818200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31818221) 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, 691678 + ... + 691723.

It is an arithmetic number, because the mean of its divisors is an integer number (8300412).

Almost surely, 2^31818223 is an apocalyptic number.

31818223 is a deficient number, since it is larger than the sum of its proper divisors (1383425).

31818223 is a wasteful number, since it uses less digits than its factorization.

31818223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1383424.

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

The square root of 31818223 is about 5640.7643985545. The cubic root of 31818223 is about 316.8779164145.

It can be divided in two parts, 31818 and 223, that added together give a square (32041 = 179²).

The spelling of 31818223 in words is "thirty-one million, eight hundred eighteen thousand, two hundred twenty-three".