3638218 has 4 divisors (see below), whose sum is σ = 5457330. Its totient is φ = 1819108.

The previous prime is 3638213. The next prime is 3638227. The reversal of 3638218 is 8128363.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8128363 = 17 ⋅478139.

It can be written as a sum of positive squares in only one way, i.e., 2778889 + 859329 = 1667^2 + 927^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 3638218.

It is not an unprimeable number, because it can be changed into a prime (3638213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 909553 + ... + 909556.

Almost surely, 2^3638218 is an apocalyptic number.

3638218 is a deficient number, since it is larger than the sum of its proper divisors (1819112).

3638218 is a wasteful number, since it uses less digits than its factorization.

3638218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819111.

The product of its digits is 6912, while the sum is 31.

The square root of 3638218 is about 1907.4113347676. The cubic root of 3638218 is about 153.8023269134.

The spelling of 3638218 in words is "three million, six hundred thirty-eight thousand, two hundred eighteen".