285191381 has 2 divisors, whose sum is σ = 285191382. Its totient is φ = 285191380.

The previous prime is 285191359. The next prime is 285191419. The reversal of 285191381 is 183191582.

It is an a-pointer prime, because the next prime (285191419) can be obtained adding 285191381 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 258244900 + 26946481 = 16070^2 + 5191^2 .

It is a cyclic number.

It is not a de Polignac number, because 285191381 - 2⁶ = 285191317 is a prime.

It is a super-2 number, since 2×285191381² = 162668247593374322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (285191341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 142595690 + 142595691.

It is an arithmetic number, because the mean of its divisors is an integer number (142595691).

Almost surely, 2^285191381 is an apocalyptic number.

It is an amenable number.

285191381 is a deficient number, since it is larger than the sum of its proper divisors (1).

285191381 is an equidigital number, since it uses as much as digits as its factorization.

285191381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 38.

The square root of 285191381 is about 16887.6102809130. The cubic root of 285191381 is about 658.2317074913.

The spelling of 285191381 in words is "two hundred eighty-five million, one hundred ninety-one thousand, three hundred eighty-one".