255803021 has 2 divisors, whose sum is σ = 255803022. Its totient is φ = 255803020.

The previous prime is 255802973. The next prime is 255803047. The reversal of 255803021 is 120308552.

It is an a-pointer prime, because the next prime (255803047) can be obtained adding 255803021 to its sum of digits (26).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 254562025 + 1240996 = 15955^2 + 1114^2 .

It is a cyclic number.

It is not a de Polignac number, because 255803021 - 2⁶ = 255802957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255803071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127901510 + 127901511.

It is an arithmetic number, because the mean of its divisors is an integer number (127901511).

Almost surely, 2^255803021 is an apocalyptic number.

It is an amenable number.

255803021 is a deficient number, since it is larger than the sum of its proper divisors (1).

255803021 is an equidigital number, since it uses as much as digits as its factorization.

255803021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 255803021 is about 15993.8432216900. The cubic root of 255803021 is about 634.7975223995.

The spelling of 255803021 in words is "two hundred fifty-five million, eight hundred three thousand, twenty-one".