381281566 has 4 divisors (see below), whose sum is σ = 571922352. Its totient is φ = 190640782.

The previous prime is 381281561. The next prime is 381281581. The reversal of 381281566 is 665182183.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 665182183 = 4273 ⋅155671.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381281561) 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 as a sum of consecutive naturals, namely, 95320390 + ... + 95320393.

It is an arithmetic number, because the mean of its divisors is an integer number (142980588).

Almost surely, 2^381281566 is an apocalyptic number.

381281566 is a deficient number, since it is larger than the sum of its proper divisors (190640786).

381281566 is a wasteful number, since it uses less digits than its factorization.

381281566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190640785.

The product of its digits is 69120, while the sum is 40.

The square root of 381281566 is about 19526.4324954662. The cubic root of 381281566 is about 725.1289923475.

The spelling of 381281566 in words is "three hundred eighty-one million, two hundred eighty-one thousand, five hundred sixty-six".