381923840 has 80 divisors (see below), whose sum is σ = 921657528. Its totient is φ = 151781376.

The previous prime is 381923837. The next prime is 381923851. The reversal of 381923840 is 48329183.

It can be written as a sum of positive squares in 4 ways, for example, as 160985344 + 220938496 = 12688^2 + 14864^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 381923794 and 381923803.

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 7 ways as a sum of consecutive naturals, for example, 493694 + ... + 494466.

Almost surely, 2^381923840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 381923840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (460828764).

381923840 is an abundant number, since it is smaller than the sum of its proper divisors (539733688).

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

381923840 is an equidigital number, since it uses as much as digits as its factorization.

381923840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 381923840 is about 19542.8718462768. The cubic root of 381923840 is about 725.5359271642.

The spelling of 381923840 in words is "three hundred eighty-one million, nine hundred twenty-three thousand, eight hundred forty".