1220320440 has 96 divisors (see below), whose sum is σ = 3986405280. Its totient is φ = 323748096.

The previous prime is 1220320427. The next prime is 1220320441. The reversal of 1220320440 is 440230221.

1220320440 is a `hidden beast` number, since 1 + 2 + 203 + 20 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220320441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62317 + ... + 79523.

It is an arithmetic number, because the mean of its divisors is an integer number (41525055).

Almost surely, 2^1220320440 is an apocalyptic number.

1220320440 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 1220320440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1993202640).

1220320440 is an abundant number, since it is smaller than the sum of its proper divisors (2766084840).

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

1220320440 is a wasteful number, since it uses less digits than its factorization.

1220320440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17421 (or 17414 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 1220320440 is about 34933.0851772356. The cubic root of 1220320440 is about 1068.6232737809.

Adding to 1220320440 its reverse (440230221), we get a palindrome (1660550661).

The spelling of 1220320440 in words is "one billion, two hundred twenty million, three hundred twenty thousand, four hundred forty".