255634781 has 2 divisors, whose sum is σ = 255634782. Its totient is φ = 255634780.

The previous prime is 255634777. The next prime is 255634817. The reversal of 255634781 is 187436552.

Together with next prime (255634817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 228281881 + 27352900 = 15109^2 + 5230^2 .

It is a cyclic number.

It is not a de Polignac number, because 255634781 - 2² = 255634777 is a prime.

It is a super-2 number, since 2×255634781² = 130698282513835922, 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 (255636781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127817390 + 127817391.

It is an arithmetic number, because the mean of its divisors is an integer number (127817391).

Almost surely, 2^255634781 is an apocalyptic number.

It is an amenable number.

255634781 is a deficient number, since it is larger than the sum of its proper divisors (1).

255634781 is an equidigital number, since it uses as much as digits as its factorization.

255634781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 201600, while the sum is 41.

The square root of 255634781 is about 15988.5828327591. The cubic root of 255634781 is about 634.6583244641.

The spelling of 255634781 in words is "two hundred fifty-five million, six hundred thirty-four thousand, seven hundred eighty-one".