255550781 has 2 divisors, whose sum is σ = 255550782. Its totient is φ = 255550780.

The previous prime is 255550759. The next prime is 255550787. The reversal of 255550781 is 187055552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 210540100 + 45010681 = 14510^2 + 6709^2 .

It is a cyclic number.

It is not a de Polignac number, because 255550781 - 2⁶ = 255550717 is a prime.

It is a super-2 number, since 2×255550781² = 130612403339419922, 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 (255550787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127775390 + 127775391.

It is an arithmetic number, because the mean of its divisors is an integer number (127775391).

Almost surely, 2^255550781 is an apocalyptic number.

It is an amenable number.

255550781 is a deficient number, since it is larger than the sum of its proper divisors (1).

255550781 is an equidigital number, since it uses as much as digits as its factorization.

255550781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 70000, while the sum is 38.

The square root of 255550781 is about 15985.9557424634. The cubic root of 255550781 is about 634.5888019218.

The spelling of 255550781 in words is "two hundred fifty-five million, five hundred fifty thousand, seven hundred eighty-one".