18218694 has 32 divisors (see below), whose sum is σ = 39561984. Its totient is φ = 5559840.

The previous prime is 18218693. The next prime is 18218723. The reversal of 18218694 is 49681281.

It is a super-2 number, since 2×18218694² = 663841622131272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18218693) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9327 + ... + 11109.

It is an arithmetic number, because the mean of its divisors is an integer number (1236312).

Almost surely, 2^18218694 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18218694, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19780992).

18218694 is an abundant number, since it is smaller than the sum of its proper divisors (21343290).

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

18218694 is a wasteful number, since it uses less digits than its factorization.

18218694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1932.

The product of its digits is 27648, while the sum is 39.

The square root of 18218694 is about 4268.3362098129. The cubic root of 18218694 is about 263.1312409117.

The spelling of 18218694 in words is "eighteen million, two hundred eighteen thousand, six hundred ninety-four".