1816257857 has 2 divisors, whose sum is σ = 1816257858. Its totient is φ = 1816257856.

The previous prime is 1816257847. The next prime is 1816257871. The reversal of 1816257857 is 7587526181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1639926016 + 176331841 = 40496^2 + 13279^2 .

It is an emirp because it is prime and its reverse (7587526181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1816257857 - 2¹⁴ = 1816241473 is a prime.

It is a super-2 number, since 2×1816257857² = 6597585206228464898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1816257847) 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 as a sum of consecutive naturals, namely, 908128928 + 908128929.

It is an arithmetic number, because the mean of its divisors is an integer number (908128929).

Almost surely, 2^1816257857 is an apocalyptic number.

It is an amenable number.

1816257857 is a deficient number, since it is larger than the sum of its proper divisors (1).

1816257857 is an equidigital number, since it uses as much as digits as its factorization.

1816257857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 940800, while the sum is 50.

The square root of 1816257857 is about 42617.5768550958. The cubic root of 1816257857 is about 1220.0917822645.

The spelling of 1816257857 in words is "one billion, eight hundred sixteen million, two hundred fifty-seven thousand, eight hundred fifty-seven".