1005638 has 4 divisors (see below), whose sum is σ = 1508460. Its totient is φ = 502818.

The previous prime is 1005637. The next prime is 1005643. The reversal of 1005638 is 8365001.

1005638 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×1005638² = 2022615574088, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1005637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 251408 + ... + 251411.

It is an arithmetic number, because the mean of its divisors is an integer number (377115).

2^1005638 is an apocalyptic number.

1005638 is a deficient number, since it is larger than the sum of its proper divisors (502822).

1005638 is an equidigital number, since it uses as much as digits as its factorization.

1005638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502821.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 1005638 is about 1002.8150377811. The cubic root of 1005638 is about 100.1875812461.

The spelling of 1005638 in words is "one million, five thousand, six hundred thirty-eight".