381309665 has 16 divisors (see below), whose sum is σ = 502770240. Its totient is φ = 275315520.

The previous prime is 381309659. The next prime is 381309667. The reversal of 381309665 is 566903183.

It is not a de Polignac number, because 381309665 - 2⁶ = 381309601 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (381309667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17294 + ... + 32583.

It is an arithmetic number, because the mean of its divisors is an integer number (31423140).

Almost surely, 2^381309665 is an apocalyptic number.

It is an amenable number.

381309665 is a deficient number, since it is larger than the sum of its proper divisors (121460575).

381309665 is a wasteful number, since it uses less digits than its factorization.

381309665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50032.

The product of its (nonzero) digits is 116640, while the sum is 41.

The square root of 381309665 is about 19527.1519940825. The cubic root of 381309665 is about 725.1468049921.

The spelling of 381309665 in words is "three hundred eighty-one million, three hundred nine thousand, six hundred sixty-five".