505005551 has 4 divisors (see below), whose sum is σ = 508395000. Its totient is φ = 501616104.

The previous prime is 505005521. The next prime is 505005559. The reversal of 505005551 is 155500505.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155500505 = 5 ⋅31100101.

It is a cyclic number.

It is not a de Polignac number, because 505005551 - 2¹⁴ = 504989167 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 505005551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505005559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1694501 + ... + 1694798.

It is an arithmetic number, because the mean of its divisors is an integer number (127098750).

Almost surely, 2^505005551 is an apocalyptic number.

505005551 is a deficient number, since it is larger than the sum of its proper divisors (3389449).

505005551 is a wasteful number, since it uses less digits than its factorization.

505005551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3389448.

The product of its (nonzero) digits is 3125, while the sum is 26.

The square root of 505005551 is about 22472.3285620338. The cubic root of 505005551 is about 796.3403419696.

The spelling of 505005551 in words is "five hundred five million, five thousand, five hundred fifty-one".