1225840 has 80 divisors (see below), whose sum is σ = 3571200. Its totient is φ = 380160.

The previous prime is 1225817. The next prime is 1225849. The reversal of 1225840 is 485221.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6061 + ... + 6259.

It is an arithmetic number, because the mean of its divisors is an integer number (44640).

2^1225840 is an apocalyptic number.

1225840 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 1225840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1785600).

1225840 is an abundant number, since it is smaller than the sum of its proper divisors (2345360).

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

1225840 is a wasteful number, since it uses less digits than its factorization.

1225840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 1225840 is about 1107.1765893479. The cubic root of 1225840 is about 107.0231993252.

It can be divided in two parts, 12 and 25840, that added together give a palindrome (25852).

The spelling of 1225840 in words is "one million, two hundred twenty-five thousand, eight hundred forty".