381947904 has 156 divisors (see below), whose sum is σ = 1189628076. Its totient is φ = 117374976.

The previous prime is 381947903. The next prime is 381947921. The reversal of 381947904 is 409749183.

It can be written as a sum of positive squares in 2 ways, for example, as 115605504 + 266342400 = 10752^2 + 16320^2 .

It is a tau number, because it is divible by the number of its divisors (156).

It is a self number, because there is not a number n which added to its sum of digits gives 381947904.

It is not an unprimeable number, because it can be changed into a prime (381947903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 478834 + ... + 479630.

It is an arithmetic number, because the mean of its divisors is an integer number (7625821).

Almost surely, 2^381947904 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 381947904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (594814038).

381947904 is an abundant number, since it is smaller than the sum of its proper divisors (807680172).

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

381947904 is a wasteful number, since it uses less digits than its factorization.

381947904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 381947904 is about 19543.4875086306. The cubic root of 381947904 is about 725.5511648705.

The spelling of 381947904 in words is "three hundred eighty-one million, nine hundred forty-seven thousand, nine hundred four".