381821664 has 48 divisors (see below), whose sum is σ = 1145467008. Its totient is φ = 109091712.

The previous prime is 381821651. The next prime is 381821669. The reversal of 381821664 is 466128183.

It is a tau number, because it is divible by the number of its divisors (48).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381821669) 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 7 ways as a sum of consecutive naturals, for example, 283422 + ... + 284765.

It is an arithmetic number, because the mean of its divisors is an integer number (23863896).

Almost surely, 2^381821664 is an apocalyptic number.

It is an amenable number.

381821664 is an abundant number, since it is smaller than the sum of its proper divisors (763645344).

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

381821664 is a wasteful number, since it uses less digits than its factorization.

381821664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568207 (or 568199 counting only the distinct ones).

The product of its digits is 55296, while the sum is 39.

The square root of 381821664 is about 19540.2575213327. The cubic root of 381821664 is about 725.4712205718.

The spelling of 381821664 in words is "three hundred eighty-one million, eight hundred twenty-one thousand, six hundred sixty-four".