1220440 has 32 divisors (see below), whose sum is σ = 2958480. Its totient is φ = 450432.

The previous prime is 1220437. The next prime is 1220489. The reversal of 1220440 is 440221.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 1220440.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 654 + ... + 1693.

2^1220440 is an apocalyptic number.

1220440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220440 is an abundant number, since it is smaller than the sum of its proper divisors (1738040).

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

1220440 is a wasteful number, since it uses less digits than its factorization.

1220440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2371 (or 2367 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 1220440 is about 1104.7352624045. The cubic root of 1220440 is about 106.8658171835.

Adding to 1220440 its reverse (440221), we get a palindrome (1660661).

The spelling of 1220440 in words is "one million, two hundred twenty thousand, four hundred forty".