1638138 has 32 divisors (see below), whose sum is σ = 3458304. Its totient is φ = 516672.

The previous prime is 1638127. The next prime is 1638139. The reversal of 1638138 is 8318361.

It is a super-2 number, since 2×1638138² = 5366992214088, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1638139) 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, 10356 + ... + 10512.

It is an arithmetic number, because the mean of its divisors is an integer number (108072).

2^1638138 is an apocalyptic number.

1638138 is an abundant number, since it is smaller than the sum of its proper divisors (1820166).

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

1638138 is a wasteful number, since it uses less digits than its factorization.

1638138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246.

The product of its digits is 3456, while the sum is 30.

The square root of 1638138 is about 1279.8976521582. The cubic root of 1638138 is about 117.8827236615.

The spelling of 1638138 in words is "one million, six hundred thirty-eight thousand, one hundred thirty-eight".