551421 has 16 divisors (see below), whose sum is σ = 880320. Its totient is φ = 339120.

The previous prime is 551407. The next prime is 551423. The reversal of 551421 is 124155.

It is not a de Polignac number, because 551421 - 2⁹ = 550909 is a prime.

551421 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 551394 and 551403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435 + ... + 1136.

It is an arithmetic number, because the mean of its divisors is an integer number (55020).

2⁵⁵¹⁴²¹ is an apocalyptic number.

It is an amenable number.

551421 is a deficient number, since it is larger than the sum of its proper divisors (328899).

551421 is a wasteful number, since it uses less digits than its factorization.

551421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1593 (or 1587 counting only the distinct ones).

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

The square root of 551421 is about 742.5772687068. The cubic root of 551421 is about 82.0026273201.

Adding to 551421 its reverse (124155), we get a palindrome (675576).

The spelling of 551421 in words is "five hundred fifty-one thousand, four hundred twenty-one".