255420123253621 has 2 divisors, whose sum is σ = 255420123253622. Its totient is φ = 255420123253620.

The previous prime is 255420123253619. The next prime is 255420123253637. The reversal of 255420123253621 is 126352321024552.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 251680424784721 + 3739698468900 = 15864439^2 + 1933830^2 .

It is a cyclic number.

It is not a de Polignac number, because 255420123253621 - 2¹ = 255420123253619 is a prime.

It is a super-2 number, since 2×255420123253621² (a number of 30 digits) contains 22 as substring.

Together with 255420123253619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (255420123223621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 127710061626810 + 127710061626811.

It is an arithmetic number, because the mean of its divisors is an integer number (127710061626811).

Almost surely, 2^{255420123253621} is an apocalyptic number.

It is an amenable number.

255420123253621 is a deficient number, since it is larger than the sum of its proper divisors (1).

255420123253621 is an equidigital number, since it uses as much as digits as its factorization.

255420123253621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864000, while the sum is 43.

The spelling of 255420123253621 in words is "two hundred fifty-five trillion, four hundred twenty billion, one hundred twenty-three million, two hundred fifty-three thousand, six hundred twenty-one".