381566256566 has 16 divisors (see below), whose sum is σ = 651528154368. Its totient is φ = 165898372200.

The previous prime is 381566256553. The next prime is 381566256569. The reversal of 381566256566 is 665652665183.

It is a super-2 number, since 2×381566256566² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381566256569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 377041250 + ... + 377042261.

It is an arithmetic number, because the mean of its divisors is an integer number (40720509648).

Almost surely, 2^381566256566 is an apocalyptic number.

381566256566 is a deficient number, since it is larger than the sum of its proper divisors (269961897802).

381566256566 is a wasteful number, since it uses less digits than its factorization.

381566256566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 754083547.

The product of its digits is 46656000, while the sum is 59.

The spelling of 381566256566 in words is "three hundred eighty-one billion, five hundred sixty-six million, two hundred fifty-six thousand, five hundred sixty-six".