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388889 = 1572477
BaseRepresentation
bin1011110111100011001
3201202110022
41132330121
544421024
612200225
73206534
oct1367431
9652408
10388889
112461a6
12169075
13108017
14a1a1b
157a35e
hex5ef19

388889 has 4 divisors (see below), whose sum is σ = 391524. Its totient is φ = 386256.

The previous prime is 388879. The next prime is 388891. The reversal of 388889 is 988883.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988883 = 7141269.

It can be written as a sum of positive squares in 2 ways, for example, as 153664 + 235225 = 392^2 + 485^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-388889 is a prime.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (388859) 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, 1082 + ... + 1395.

It is an arithmetic number, because the mean of its divisors is an integer number (97881).

2388889 is an apocalyptic number.

It is an amenable number.

388889 is a deficient number, since it is larger than the sum of its proper divisors (2635).

388889 is a wasteful number, since it uses less digits than its factorization.

388889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2634.

The product of its digits is 110592, while the sum is 44.

The square root of 388889 is about 623.6096535494. The cubic root of 388889 is about 72.9919926164.

The spelling of 388889 in words is "three hundred eighty-eight thousand, eight hundred eighty-nine".

Divisors: 1 157 2477 388889