381912857 has 2 divisors, whose sum is σ = 381912858. Its totient is φ = 381912856.

The previous prime is 381912851. The next prime is 381912877. The reversal of 381912857 is 758219183.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 377486041 + 4426816 = 19429^2 + 2104^2 .

It is an emirp because it is prime and its reverse (758219183) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 381912857 - 2⁶ = 381912793 is a prime.

It is a super-3 number, since 3×381912857³ (a number of 27 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (381912851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190956428 + 190956429.

It is an arithmetic number, because the mean of its divisors is an integer number (190956429).

Almost surely, 2^381912857 is an apocalyptic number.

It is an amenable number.

381912857 is a deficient number, since it is larger than the sum of its proper divisors (1).

381912857 is an equidigital number, since it uses as much as digits as its factorization.

381912857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 44.

The square root of 381912857 is about 19542.5908466610. The cubic root of 381912857 is about 725.5289723418.

The spelling of 381912857 in words is "three hundred eighty-one million, nine hundred twelve thousand, eight hundred fifty-seven".