255251781 has 6 divisors (see below), whose sum is σ = 368697030. Its totient is φ = 170167848.

The previous prime is 255251779. The next prime is 255251791. The reversal of 255251781 is 187152552.

It can be written as a sum of positive squares in only one way, i.e., 245423556 + 9828225 = 15666^2 + 3135^2 .

It is not a de Polignac number, because 255251781 - 2¹ = 255251779 is a prime.

It is a super-2 number, since 2×255251781² = 130306943407343922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255251701) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14180646 + ... + 14180663.

It is an arithmetic number, because the mean of its divisors is an integer number (61449505).

Almost surely, 2^255251781 is an apocalyptic number.

It is an amenable number.

255251781 is a deficient number, since it is larger than the sum of its proper divisors (113445249).

255251781 is a wasteful number, since it uses less digits than its factorization.

255251781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28361315 (or 28361312 counting only the distinct ones).

The product of its digits is 28000, while the sum is 36.

The square root of 255251781 is about 15976.6010465305. The cubic root of 255251781 is about 634.3412110778.

The spelling of 255251781 in words is "two hundred fifty-five million, two hundred fifty-one thousand, seven hundred eighty-one".