1018638 has 12 divisors (see below), whose sum is σ = 2207088. Its totient is φ = 339540.

The previous prime is 1018621. The next prime is 1018643. The reversal of 1018638 is 8368101.

1018638 is a `hidden beast` number, since 10 + 18 + 638 = 666.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 28278 + ... + 28313.

It is an arithmetic number, because the mean of its divisors is an integer number (183924).

2^1018638 is an apocalyptic number.

1018638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1018638 is an abundant number, since it is smaller than the sum of its proper divisors (1188450).

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

1018638 is a wasteful number, since it uses less digits than its factorization.

1018638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56599 (or 56596 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 1018638 is about 1009.2759781150. The cubic root of 1018638 is about 100.6174464193.

The spelling of 1018638 in words is "one million, eighteen thousand, six hundred thirty-eight".