255500021 has 8 divisors (see below), whose sum is σ = 309176640. Its totient is φ = 206117568.

The previous prime is 255499999. The next prime is 255500039. The reversal of 255500021 is 120005552.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 255500021 - 2¹⁴ = 255483637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 255499966 and 255500002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255500051) 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 7 ways as a sum of consecutive naturals, for example, 1073411 + ... + 1073648.

It is an arithmetic number, because the mean of its divisors is an integer number (38647080).

Almost surely, 2^255500021 is an apocalyptic number.

It is an amenable number.

255500021 is a deficient number, since it is larger than the sum of its proper divisors (53676619).

255500021 is a wasteful number, since it uses less digits than its factorization.

255500021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2147083.

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 255500021 is about 15984.3680200376. The cubic root of 255500021 is about 634.5467830578.

Adding to 255500021 its reverse (120005552), we get a palindrome (375505573).

The spelling of 255500021 in words is "two hundred fifty-five million, five hundred thousand, twenty-one".