18218634 has 16 divisors (see below), whose sum is σ = 41642688. Its totient is φ = 5205312.

The previous prime is 18218617. The next prime is 18218639. The reversal of 18218634 is 43681281.

It is a junction number, because it is equal to n+sod(n) for n = 18218595 and 18218604.

It is not an unprimeable number, because it can be changed into a prime (18218639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 216847 + ... + 216930.

It is an arithmetic number, because the mean of its divisors is an integer number (2602668).

Almost surely, 2^18218634 is an apocalyptic number.

18218634 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

18218634 is an abundant number, since it is smaller than the sum of its proper divisors (23424054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18218634 is a wasteful number, since it uses less digits than its factorization.

18218634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433789.

The product of its digits is 9216, while the sum is 33.

The square root of 18218634 is about 4268.3291813074. The cubic root of 18218634 is about 263.1309520529.

The spelling of 18218634 in words is "eighteen million, two hundred eighteen thousand, six hundred thirty-four".