1311640440 has 128 divisors (see below), whose sum is σ = 4545227520. Its totient is φ = 299264000.

The previous prime is 1311640403. The next prime is 1311640459. The reversal of 1311640440 is 440461131.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1311640440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6786 + ... + 51665.

It is an arithmetic number, because the mean of its divisors is an integer number (35509590).

Almost surely, 2^1311640440 is an apocalyptic number.

1311640440 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 1311640440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2272613760).

1311640440 is an abundant number, since it is smaller than the sum of its proper divisors (3233587080).

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

1311640440 is a wasteful number, since it uses less digits than its factorization.

1311640440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58493 (or 58489 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1311640440 is about 36216.5768675064. The cubic root of 1311640440 is about 1094.6407194763.

The spelling of 1311640440 in words is "one billion, three hundred eleven million, six hundred forty thousand, four hundred forty".