1638867 has 4 divisors (see below), whose sum is σ = 2185160. Its totient is φ = 1092576.

The previous prime is 1638821. The next prime is 1638869. The reversal of 1638867 is 7688361.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1638867 - 2¹¹ = 1636819 is a prime.

It is a D-number.

It is a Duffinian number.

1638867 is a lucky number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (1638869) 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, 273142 + ... + 273147.

It is an arithmetic number, because the mean of its divisors is an integer number (546290).

2^1638867 is an apocalyptic number.

1638867 is a deficient number, since it is larger than the sum of its proper divisors (546293).

1638867 is an equidigital number, since it uses as much as digits as its factorization.

1638867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546292.

The product of its digits is 48384, while the sum is 39.

The square root of 1638867 is about 1280.1824088777. The cubic root of 1638867 is about 117.9002076913.

It can be divided in two parts, 16 and 38867, that added together give a palindrome (38883).

The spelling of 1638867 in words is "one million, six hundred thirty-eight thousand, eight hundred sixty-seven".