1331405440 has 32 divisors (see below), whose sum is σ = 3182892660. Its totient is φ = 532561920.

The previous prime is 1331405429. The next prime is 1331405477. The reversal of 1331405440 is 445041331.

It can be written as a sum of positive squares in 2 ways, for example, as 1263375936 + 68029504 = 35544^2 + 8248^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1039521 + ... + 1040800.

Almost surely, 2^1331405440 is an apocalyptic number.

1331405440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1331405440 is an abundant number, since it is smaller than the sum of its proper divisors (1851487220).

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

1331405440 is an equidigital number, since it uses as much as digits as its factorization.

1331405440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2080340 (or 2080328 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 1331405440 is about 36488.4288508015. The cubic root of 1331405440 is about 1100.1116801211. Note that the first 3 decimals are identical.

Adding to 1331405440 its reverse (445041331), we get a palindrome (1776446771).

The spelling of 1331405440 in words is "one billion, three hundred thirty-one million, four hundred five thousand, four hundred forty".