381643920 has 320 divisors, whose sum is σ = 1539901440. Its totient is φ = 85059072.

The previous prime is 381643909. The next prime is 381643939. The reversal of 381643920 is 29346183.

381643920 is a `hidden beast` number, since 3 + 8 + 1 + 643 + 9 + 2 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 649867 + ... + 650453.

It is an arithmetic number, because the mean of its divisors is an integer number (4812192).

Almost surely, 2^381643920 is an apocalyptic number.

381643920 is a gapful number since it is divisible by the number (30) 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 381643920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (769950720).

381643920 is an abundant number, since it is smaller than the sum of its proper divisors (1158257520).

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

381643920 is a wasteful number, since it uses less digits than its factorization.

381643920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659 (or 647 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 381643920 is about 19535.7088430392. The cubic root of 381643920 is about 725.3586303383.

The spelling of 381643920 in words is "three hundred eighty-one million, six hundred forty-three thousand, nine hundred twenty".