1331220440 has 64 divisors (see below), whose sum is σ = 3281472000. Its totient is φ = 482016640.

The previous prime is 1331220419. The next prime is 1331220463. The reversal of 1331220440 is 440221331.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98831 + ... + 111489.

It is an arithmetic number, because the mean of its divisors is an integer number (51273000).

Almost surely, 2^1331220440 is an apocalyptic number.

1331220440 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 1331220440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1640736000).

1331220440 is an abundant number, since it is smaller than the sum of its proper divisors (1950251560).

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

1331220440 is a wasteful number, since it uses less digits than its factorization.

1331220440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12920 (or 12916 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 1331220440 is about 36485.8937125021. The cubic root of 1331220440 is about 1100.0607239205.

Adding to 1331220440 its reverse (440221331), we get a palindrome (1771441771).

The spelling of 1331220440 in words is "one billion, three hundred thirty-one million, two hundred twenty thousand, four hundred forty".