1381081536 has 112 divisors (see below), whose sum is σ = 4170050080. Its totient is φ = 447897600.

The previous prime is 1381081469. The next prime is 1381081549. The reversal of 1381081536 is 6351801831.

1381081536 is a `hidden beast` number, since 1 + 38 + 10 + 81 + 536 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1381081536.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53136 + ... + 74736.

It is an arithmetic number, because the mean of its divisors is an integer number (37232590).

Almost surely, 2^1381081536 is an apocalyptic number.

1381081536 is a gapful number since it is divisible by the number (16) 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 1381081536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2085025040).

1381081536 is an abundant number, since it is smaller than the sum of its proper divisors (2788968544).

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

1381081536 is a wasteful number, since it uses less digits than its factorization.

1381081536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21659 (or 21643 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 1381081536 is about 37162.9053761947. The cubic root of 1381081536 is about 1113.6270541882.

The spelling of 1381081536 in words is "one billion, three hundred eighty-one million, eighty-one thousand, five hundred thirty-six".