381791556 has 30 divisors (see below), whose sum is σ = 998079390. Its totient is φ = 127263744.

The previous prime is 381791551. The next prime is 381791561. The reversal of 381791556 is 655197183.

It is a happy number.

381791556 is a `hidden beast` number, since 3 + 8 + 1 + 7 + 91 + 556 = 666.

It is an interprime number because it is at equal distance from previous prime (381791551) and next prime (381791561).

It can be written as a sum of positive squares in only one way, i.e., 366109956 + 15681600 = 19134^2 + 3960^2 .

It is a super-2 number, since 2×381791556² = 291529584465802272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (381791551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 588861 + ... + 589508.

It is an arithmetic number, because the mean of its divisors is an integer number (33269313).

Almost surely, 2^381791556 is an apocalyptic number.

381791556 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

381791556 is an abundant number, since it is smaller than the sum of its proper divisors (616287834).

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

381791556 is a wasteful number, since it uses less digits than its factorization.

381791556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1178385 (or 1178374 counting only the distinct ones).

The product of its digits is 226800, while the sum is 45.

The square root of 381791556 is about 19539.4870966461. The cubic root of 381791556 is about 725.4521514062.

The spelling of 381791556 in words is "three hundred eighty-one million, seven hundred ninety-one thousand, five hundred fifty-six".