1388920 has 32 divisors (see below), whose sum is σ = 3366720. Its totient is φ = 512640.
The previous prime is 1388887. The next prime is 1388927. The reversal of 1388920 is 298831.
It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.
It is an Ulam number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1388927) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 816 + ... + 1855.
It is an arithmetic number, because the mean of its divisors is an integer number (105210).
21388920 is an apocalyptic number.
1388920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
1388920 is an abundant number, since it is smaller than the sum of its proper divisors (1977800).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1388920 is a wasteful number, since it uses less digits than its factorization.
1388920 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2695 (or 2691 counting only the distinct ones).
The product of its (nonzero) digits is 3456, while the sum is 31.
The square root of 1388920 is about 1178.5245012302. The cubic root of 1388920 is about 111.5729914129.
It can be divided in two parts, 13 and 88920, that multiplied together give a triangular number (1155960 = T1520).
The spelling of 1388920 in words is "one million, three hundred eighty-eight thousand, nine hundred twenty".
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