1638879 has 8 divisors (see below), whose sum is σ = 2383872. Its totient is φ = 993240.

The previous prime is 1638869. The next prime is 1638899. The reversal of 1638879 is 9788361.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1638879 - 2¹⁹ = 1114591 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1638879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24799 + ... + 24864.

It is an arithmetic number, because the mean of its divisors is an integer number (297984).

2^1638879 is an apocalyptic number.

1638879 is a deficient number, since it is larger than the sum of its proper divisors (744993).

1638879 is a wasteful number, since it uses less digits than its factorization.

1638879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49677.

The product of its digits is 72576, while the sum is 42.

The square root of 1638879 is about 1280.1870957012. The cubic root of 1638879 is about 117.9004954509.

The spelling of 1638879 in words is "one million, six hundred thirty-eight thousand, eight hundred seventy-nine".