281816375381 has 2 divisors, whose sum is σ = 281816375382. Its totient is φ = 281816375380.

The previous prime is 281816375293. The next prime is 281816375383. The reversal of 281816375381 is 183573618182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157556600356 + 124259775025 = 396934^2 + 352505^2 .

It is a cyclic number.

It is not a de Polignac number, because 281816375381 - 2¹⁴ = 281816358997 is a prime.

It is a super-2 number, since 2×281816375381² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 281816375383, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (281816375383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140908187690 + 140908187691.

It is an arithmetic number, because the mean of its divisors is an integer number (140908187691).

Almost surely, 2^281816375381 is an apocalyptic number.

It is an amenable number.

281816375381 is a deficient number, since it is larger than the sum of its proper divisors (1).

281816375381 is an equidigital number, since it uses as much as digits as its factorization.

281816375381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1935360, while the sum is 53.

The spelling of 281816375381 in words is "two hundred eighty-one billion, eight hundred sixteen million, three hundred seventy-five thousand, three hundred eighty-one".