255505551 has 24 divisors (see below), whose sum is σ = 413529984. Its totient is φ = 139653360.

The previous prime is 255505517. The next prime is 255505553. The reversal of 255505551 is 155505552.

It is not a de Polignac number, because 255505551 - 2⁷ = 255505423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (255505553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34405 + ... + 41166.

It is an arithmetic number, because the mean of its divisors is an integer number (17230416).

Almost surely, 2^255505551 is an apocalyptic number.

255505551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

255505551 is a deficient number, since it is larger than the sum of its proper divisors (158024433).

255505551 is a wasteful number, since it uses less digits than its factorization.

255505551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75611 (or 75604 counting only the distinct ones).

The product of its (nonzero) digits is 31250, while the sum is 33.

The square root of 255505551 is about 15984.5410006043. The cubic root of 255505551 is about 634.5513610331.

Subtracting from 255505551 its reverse (155505552), we obtain a palindrome (99999999).

The spelling of 255505551 in words is "two hundred fifty-five million, five hundred five thousand, five hundred fifty-one".