255355432421021 has 2 divisors, whose sum is σ = 255355432421022. Its totient is φ = 255355432421020.

The previous prime is 255355432420961. The next prime is 255355432421093. The reversal of 255355432421021 is 120124234553552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180461743296025 + 74893689124996 = 13433605^2 + 8654114^2 .

It is a cyclic number.

It is not a de Polignac number, because 255355432421021 - 2¹⁸ = 255355432158877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255355432429021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127677716210510 + 127677716210511.

It is an arithmetic number, because the mean of its divisors is an integer number (127677716210511).

Almost surely, 2^{255355432421021} is an apocalyptic number.

It is an amenable number.

255355432421021 is a deficient number, since it is larger than the sum of its proper divisors (1).

255355432421021 is an equidigital number, since it uses as much as digits as its factorization.

255355432421021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440000, while the sum is 44.

Adding to 255355432421021 its reverse (120124234553552), we get a palindrome (375479666974573).

The spelling of 255355432421021 in words is "two hundred fifty-five trillion, three hundred fifty-five billion, four hundred thirty-two million, four hundred twenty-one thousand, twenty-one".