1223440 has 40 divisors (see below), whose sum is σ = 2921688. Its totient is φ = 476160.

The previous prime is 1223437. The next prime is 1223447. The reversal of 1223440 is 443221.

It can be written as a sum of positive squares in 4 ways, for example, as 4624 + 1218816 = 68^2 + 1104^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223447) 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, 3094 + ... + 3466.

2^1223440 is an apocalyptic number.

1223440 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 1223440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1460844).

1223440 is an abundant number, since it is smaller than the sum of its proper divisors (1698248).

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

1223440 is a wasteful number, since it uses less digits than its factorization.

1223440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427 (or 421 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 1223440 is about 1106.0922203867. The cubic root of 1223440 is about 106.9533088859.

Adding to 1223440 its reverse (443221), we get a palindrome (1666661).

The spelling of 1223440 in words is "one million, two hundred twenty-three thousand, four hundred forty".