8381440 has 44 divisors (see below), whose sum is σ = 20117916. Its totient is φ = 3350528.

The previous prime is 8381437. The next prime is 8381447. The reversal of 8381440 is 441838.

It can be written as a sum of positive squares in 2 ways, for example, as 1327104 + 7054336 = 1152^2 + 2656^2 .

It is a junction number, because it is equal to n+sod(n) for n = 8381399 and 8381408.

It is not an unprimeable number, because it can be changed into a prime (8381447) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 4302 + ... + 5938.

Almost surely, 2^8381440 is an apocalyptic number.

8381440 is a gapful number since it is divisible by the number (80) 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 8381440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10058958).

8381440 is an abundant number, since it is smaller than the sum of its proper divisors (11736476).

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

8381440 is a wasteful number, since it uses less digits than its factorization.

8381440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662 (or 1644 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 8381440 is about 2895.0716744150. The cubic root of 8381440 is about 203.1294441631.

It can be divided in two parts, 838 and 1440, that added together give a triangular number (2278 = T₆₇).

The spelling of 8381440 in words is "eight million, three hundred eighty-one thousand, four hundred forty".