255021021 has 16 divisors (see below), whose sum is σ = 397694400. Its totient is φ = 161065584.

The previous prime is 255021017. The next prime is 255021023. The reversal of 255021021 is 120120552.

It is not a de Polignac number, because 255021021 - 2² = 255021017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 255020985 and 255021003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255021023) 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 in 15 ways as a sum of consecutive naturals, for example, 248046 + ... + 249071.

It is an arithmetic number, because the mean of its divisors is an integer number (24855900).

Almost surely, 2^255021021 is an apocalyptic number.

It is an amenable number.

255021021 is a deficient number, since it is larger than the sum of its proper divisors (142673379).

255021021 is a wasteful number, since it uses less digits than its factorization.

255021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497145 (or 497139 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 255021021 is about 15969.3776021484. The cubic root of 255021021 is about 634.1499950280.

Adding to 255021021 its reverse (120120552), we get a palindrome (375141573).

The spelling of 255021021 in words is "two hundred fifty-five million, twenty-one thousand, twenty-one".