381857129 has 2 divisors, whose sum is σ = 381857130. Its totient is φ = 381857128.

The previous prime is 381857033. The next prime is 381857143. The reversal of 381857129 is 921758183.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 256864729 + 124992400 = 16027^2 + 11180^2 .

It is an emirp because it is prime and its reverse (921758183) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 381857129 - 2²⁰ = 380808553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 381857129.

It is not a weakly prime, because it can be changed into another prime (381857159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190928564 + 190928565.

It is an arithmetic number, because the mean of its divisors is an integer number (190928565).

Almost surely, 2^381857129 is an apocalyptic number.

It is an amenable number.

381857129 is a deficient number, since it is larger than the sum of its proper divisors (1).

381857129 is an equidigital number, since it uses as much as digits as its factorization.

381857129 is an odious number, because the sum of its binary digits is odd.

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

The square root of 381857129 is about 19541.1649857423. The cubic root of 381857129 is about 725.4936813545.

The spelling of 381857129 in words is "three hundred eighty-one million, eight hundred fifty-seven thousand, one hundred twenty-nine".