381642666 has 8 divisors (see below), whose sum is σ = 763285344. Its totient is φ = 127214220.

The previous prime is 381642661. The next prime is 381642689. The reversal of 381642666 is 666246183.

It is a sphenic number, since it is the product of 3 distinct primes.

381642666 is an admirable number.

It is a super-2 number, since 2×381642666² = 291302249023175112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (381642661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31803550 + ... + 31803561.

It is an arithmetic number, because the mean of its divisors is an integer number (95410668).

Almost surely, 2^381642666 is an apocalyptic number.

381642666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

381642666 is a wasteful number, since it uses less digits than its factorization.

381642666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63607116.

The product of its digits is 248832, while the sum is 42.

The square root of 381642666 is about 19535.6767479399. The cubic root of 381642666 is about 725.3578358798.

The spelling of 381642666 in words is "three hundred eighty-one million, six hundred forty-two thousand, six hundred sixty-six".