381806565 has 32 divisors (see below), whose sum is σ = 700206336. Its totient is φ = 174028800.

The previous prime is 381806549. The next prime is 381806599. The reversal of 381806565 is 565608183.

It is not a de Polignac number, because 381806565 - 2⁴ = 381806549 is a prime.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 31915 + ... + 42215.

It is an arithmetic number, because the mean of its divisors is an integer number (21881448).

Almost surely, 2^381806565 is an apocalyptic number.

381806565 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

381806565 is a deficient number, since it is larger than the sum of its proper divisors (318399771).

381806565 is a wasteful number, since it uses less digits than its factorization.

381806565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10669.

The product of its (nonzero) digits is 172800, while the sum is 42.

The square root of 381806565 is about 19539.8711612948. The cubic root of 381806565 is about 725.4616576132.

The spelling of 381806565 in words is "three hundred eighty-one million, eight hundred six thousand, five hundred sixty-five".