1581178240 has 128 divisors (see below), whose sum is σ = 3974572800. Its totient is φ = 600348672.

The previous prime is 1581178199. The next prime is 1581178259. The reversal of 1581178240 is 428711851.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 1581178240.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2399031 + ... + 2399689.

It is an arithmetic number, because the mean of its divisors is an integer number (31051350).

Almost surely, 2^1581178240 is an apocalyptic number.

1581178240 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 1581178240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1987286400).

1581178240 is an abundant number, since it is smaller than the sum of its proper divisors (2393394560).

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

1581178240 is a wasteful number, since it uses less digits than its factorization.

1581178240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 864 (or 852 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 37.

The square root of 1581178240 is about 39764.0319887207. The cubic root of 1581178240 is about 1165.0027298284.

The spelling of 1581178240 in words is "one billion, five hundred eighty-one million, one hundred seventy-eight thousand, two hundred forty".