381131309 has 16 divisors (see below), whose sum is σ = 417912768. Its totient is φ = 345451392.

The previous prime is 381131291. The next prime is 381131323. The reversal of 381131309 is 903131183.

It is a de Polignac number, because none of the positive numbers 2^k-381131309 is a prime.

It is a super-2 number, since 2×381131309² = 290522149400106962, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381131609) 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 in 15 ways as a sum of consecutive naturals, for example, 406289 + ... + 407225.

It is an arithmetic number, because the mean of its divisors is an integer number (26119548).

Almost surely, 2^381131309 is an apocalyptic number.

It is an amenable number.

381131309 is a deficient number, since it is larger than the sum of its proper divisors (36781459).

381131309 is a wasteful number, since it uses less digits than its factorization.

381131309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1484.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 381131309 is about 19522.5845881123. The cubic root of 381131309 is about 725.0337258984.

The spelling of 381131309 in words is "three hundred eighty-one million, one hundred thirty-one thousand, three hundred nine".