1387638 has 32 divisors (see below), whose sum is σ = 3525120. Its totient is φ = 396360.

The previous prime is 1387601. The next prime is 1387649. The reversal of 1387638 is 8367831.

1387638 is a `hidden beast` number, since 13 + 8 + 7 + 638 = 666.

It is a Curzon 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 15 ways as a sum of consecutive naturals, for example, 1458 + ... + 2213.

It is an arithmetic number, because the mean of its divisors is an integer number (110160).

2^1387638 is an apocalyptic number.

1387638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1387638 is an abundant number, since it is smaller than the sum of its proper divisors (2137482).

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

1387638 is a wasteful number, since it uses less digits than its factorization.

1387638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3689 (or 3683 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 1387638 is about 1177.9804752202. The cubic root of 1387638 is about 111.5386528366.

It can be divided in two parts, 1387 and 638, that added together give a square (2025 = 45²).

The spelling of 1387638 in words is "one million, three hundred eighty-seven thousand, six hundred thirty-eight".