1381128840 has 768 divisors, whose sum is σ = 6071500800. Its totient is φ = 272802816.

The previous prime is 1381128823. The next prime is 1381128851. The reversal of 1381128840 is 488211831.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1381128795 and 1381128804.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 29385697 + ... + 29385743.

It is an arithmetic number, because the mean of its divisors is an integer number (7905600).

Almost surely, 2^1381128840 is an apocalyptic number.

1381128840 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 1381128840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3035750400).

1381128840 is an abundant number, since it is smaller than the sum of its proper divisors (4690371960).

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

1381128840 is a wasteful number, since it uses less digits than its factorization.

1381128840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 1381128840 is about 37163.5418118349. The cubic root of 1381128840 is about 1113.6397684780.

The spelling of 1381128840 in words is "one billion, three hundred eighty-one million, one hundred twenty-eight thousand, eight hundred forty".