381646566 has 96 divisors (see below), whose sum is σ = 1037836800. Its totient is φ = 102612096.

The previous prime is 381646523. The next prime is 381646571. The reversal of 381646566 is 665646183.

381646566 is a `hidden beast` number, since 3 + 81 + 6 + 4 + 6 + 566 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 54535 + ... + 61133.

It is an arithmetic number, because the mean of its divisors is an integer number (10810800).

Almost surely, 2^381646566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 381646566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (518918400).

381646566 is an abundant number, since it is smaller than the sum of its proper divisors (656190234).

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

381646566 is a wasteful number, since it uses less digits than its factorization.

381646566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6640 (or 6628 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 381646566 is about 19535.7765650613. The cubic root of 381646566 is about 725.3603066779.

The spelling of 381646566 in words is "three hundred eighty-one million, six hundred forty-six thousand, five hundred sixty-six".