5551821 has 48 divisors (see below), whose sum is σ = 9504768. Its totient is φ = 3207600.

The previous prime is 5551807. The next prime is 5551829. The reversal of 5551821 is 1281555.

It is not a de Polignac number, because 5551821 - 2⁶ = 5551757 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5551829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 82830 + ... + 82896.

It is an arithmetic number, because the mean of its divisors is an integer number (198016).

Almost surely, 2^5551821 is an apocalyptic number.

It is an amenable number.

5551821 is a deficient number, since it is larger than the sum of its proper divisors (3952947).

5551821 is a wasteful number, since it uses less digits than its factorization.

5551821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 112 counting only the distinct ones).

The product of its digits is 2000, while the sum is 27.

The square root of 5551821 is about 2356.2302519066. The cubic root of 5551821 is about 177.0700670600.

The spelling of 5551821 in words is "five million, five hundred fifty-one thousand, eight hundred twenty-one".