55384821 has 12 divisors (see below), whose sum is σ = 80965248. Its totient is φ = 36477864.

The previous prime is 55384811. The next prime is 55384831. The reversal of 55384821 is 12848355.

It is a happy number.

55384821 is a `hidden beast` number, since 553 + 84 + 8 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (55384811) and next prime (55384831).

It is not a de Polignac number, because 55384821 - 2¹¹ = 55382773 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55384811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36325 + ... + 37818.

It is an arithmetic number, because the mean of its divisors is an integer number (6747104).

Almost surely, 2^55384821 is an apocalyptic number.

It is an amenable number.

55384821 is a deficient number, since it is larger than the sum of its proper divisors (25580427).

55384821 is a wasteful number, since it uses less digits than its factorization.

55384821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74232 (or 74229 counting only the distinct ones).

The product of its digits is 38400, while the sum is 36.

The square root of 55384821 is about 7442.0978897083. The cubic root of 55384821 is about 381.1801285195.

The spelling of 55384821 in words is "fifty-five million, three hundred eighty-four thousand, eight hundred twenty-one".