1581338840 has 96 divisors (see below), whose sum is σ = 3848160960. Its totient is φ = 584409600.

The previous prime is 1581338833. The next prime is 1581338879. The reversal of 1581338840 is 488331851.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 590705 + ... + 593375.

It is an arithmetic number, because the mean of its divisors is an integer number (40085010).

Almost surely, 2^1581338840 is an apocalyptic number.

1581338840 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 1581338840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1924080480).

1581338840 is an abundant number, since it is smaller than the sum of its proper divisors (2266822120).

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

1581338840 is a wasteful number, since it uses less digits than its factorization.

1581338840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2761 (or 2738 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 41.

The square root of 1581338840 is about 39766.0513503667. The cubic root of 1581338840 is about 1165.0421715349.

The spelling of 1581338840 in words is "one billion, five hundred eighty-one million, three hundred thirty-eight thousand, eight hundred forty".