1391041440 has 144 divisors (see below), whose sum is σ = 4862914056. Its totient is φ = 361881600.

The previous prime is 1391041427. The next prime is 1391041441. The reversal of 1391041440 is 441401931.

It can be written as a sum of positive squares in 4 ways, for example, as 535829904 + 855211536 = 23148^2 + 29244^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is not an unprimeable number, because it can be changed into a prime (1391041441) 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, 47260 + ... + 70820.

Almost surely, 2^1391041440 is an apocalyptic number.

1391041440 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 1391041440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2431457028).

1391041440 is an abundant number, since it is smaller than the sum of its proper divisors (3471872616).

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

1391041440 is a wasteful number, since it uses less digits than its factorization.

1391041440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23623 (or 23612 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 1391041440 is about 37296.6679476867. The cubic root of 1391041440 is about 1116.2976814096.

The spelling of 1391041440 in words is "one billion, three hundred ninety-one million, forty-one thousand, four hundred forty".