381649866 has 32 divisors (see below), whose sum is σ = 848537088. Its totient is φ = 113641920.

The previous prime is 381649843. The next prime is 381649867. The reversal of 381649866 is 668946183.

It is not an unprimeable number, because it can be changed into a prime (381649867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76501 + ... + 81336.

It is an arithmetic number, because the mean of its divisors is an integer number (26516784).

Almost surely, 2^381649866 is an apocalyptic number.

381649866 is an abundant number, since it is smaller than the sum of its proper divisors (466887222).

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

381649866 is a wasteful number, since it uses less digits than its factorization.

381649866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157886.

The product of its digits is 1492992, while the sum is 51.

The square root of 381649866 is about 19535.8610253042. The cubic root of 381649866 is about 725.3623973401.

The spelling of 381649866 in words is "three hundred eighty-one million, six hundred forty-nine thousand, eight hundred sixty-six".