18213623 has 4 divisors (see below), whose sum is σ = 18234528. Its totient is φ = 18192720.

The previous prime is 18213617. The next prime is 18213659. The reversal of 18213623 is 32631281.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32631281 = 43 ⋅758867.

It is a cyclic number.

It is not a de Polignac number, because 18213623 - 2⁸ = 18213367 is a prime.

It is a super-2 number, since 2×18213623² = 663472125572258, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18213592 and 18213601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18213823) 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, 9086 + ... + 10907.

It is an arithmetic number, because the mean of its divisors is an integer number (4558632).

Almost surely, 2^18213623 is an apocalyptic number.

18213623 is a deficient number, since it is larger than the sum of its proper divisors (20905).

18213623 is an equidigital number, since it uses as much as digits as its factorization.

18213623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20904.

The product of its digits is 1728, while the sum is 26.

The square root of 18213623 is about 4267.7421431010. The cubic root of 18213623 is about 263.1068252878.

The spelling of 18213623 in words is "eighteen million, two hundred thirteen thousand, six hundred twenty-three".