381681664 has 92 divisors (see below), whose sum is σ = 939523984. Its totient is φ = 150994944.

The previous prime is 381681661. The next prime is 381681683. The reversal of 381681664 is 466186183.

It is a happy number.

Its product of digits (165888) is a multiple of the sum of its prime factors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 381681664.

It is not an unprimeable number, because it can be changed into a prime (381681661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29360122 + ... + 29360134.

Almost surely, 2^381681664 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 381681664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (469761992).

381681664 is an abundant number, since it is smaller than the sum of its proper divisors (557842320).

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

381681664 is an frugal number, since it uses more digits than its factorization.

381681664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 22 counting only the distinct ones).

The product of its digits is 165888, while the sum is 43.

The square root of 381681664 is about 19536.6748450190. The cubic root of 381681664 is about 725.3825418364.

The spelling of 381681664 in words is "three hundred eighty-one million, six hundred eighty-one thousand, six hundred sixty-four".