551405 has 4 divisors (see below), whose sum is σ = 661692. Its totient is φ = 441120.

The previous prime is 551387. The next prime is 551407. The reversal of 551405 is 504155.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 178084 + 373321 = 422^2 + 611^2 .

It is a de Polignac number, because none of the positive numbers 2^k-551405 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55136 + ... + 55145.

It is an arithmetic number, because the mean of its divisors is an integer number (165423).

2⁵⁵¹⁴⁰⁵ is an apocalyptic number.

It is an amenable number.

551405 is a deficient number, since it is larger than the sum of its proper divisors (110287).

551405 is a wasteful number, since it uses less digits than its factorization.

551405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110286.

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

The square root of 551405 is about 742.5664953390. The cubic root of 551405 is about 82.0018341846.

The spelling of 551405 in words is "five hundred fifty-one thousand, four hundred five".