551639 has 12 divisors (see below), whose sum is σ = 625632. Its totient is φ = 485760.

The previous prime is 551597. The next prime is 551651. The reversal of 551639 is 936155.

It is not a de Polignac number, because 551639 - 2¹⁶ = 486103 is a prime.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (551659) 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 11 ways as a sum of consecutive naturals, for example, 5639 + ... + 5735.

It is an arithmetic number, because the mean of its divisors is an integer number (52136).

2⁵⁵¹⁶³⁹ is an apocalyptic number.

551639 is a deficient number, since it is larger than the sum of its proper divisors (73993).

551639 is a wasteful number, since it uses less digits than its factorization.

551639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 155 counting only the distinct ones).

The product of its digits is 4050, while the sum is 29.

The square root of 551639 is about 742.7240402734. The cubic root of 551639 is about 82.0134322632.

It can be divided in two parts, 5516 and 39, that added together give a palindrome (5555).

The spelling of 551639 in words is "five hundred fifty-one thousand, six hundred thirty-nine".