1213440 has 88 divisors (see below), whose sum is σ = 3930240. Its totient is φ = 319488.
The previous prime is 1213439. The next prime is 1213451. The reversal of 1213440 is 443121.
It is a Harshad number since it is a multiple of its sum of digits (15).
It is a congruent number.
It is an unprimeable number.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15321 + ... + 15399.
21213440 is an apocalyptic number.
1213440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 1213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1965120).
1213440 is an abundant number, since it is smaller than the sum of its proper divisors (2716800).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
1213440 is an equidigital number, since it uses as much as digits as its factorization.
1213440 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 107 (or 89 counting only the distinct ones).
The product of its (nonzero) digits is 96, while the sum is 15.
The square root of 1213440 is about 1101.5625265957. The cubic root of 1213440 is about 106.6611108217.
Adding to 1213440 its reverse (443121), we get a palindrome (1656561).
It can be divided in two parts, 1213 and 440, that added together give a triangular number (1653 = T57).
The spelling of 1213440 in words is "one million, two hundred thirteen thousand, four hundred forty".
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