55082821 has 4 divisors (see below), whose sum is σ = 55516672. Its totient is φ = 54648972.

The previous prime is 55082809. The next prime is 55082849. The reversal of 55082821 is 12828055.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12828055 = 5 ⋅2565611.

It is a cyclic number.

It is not a de Polignac number, because 55082821 - 2²⁵ = 21528389 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 (55082801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 216735 + ... + 216988.

It is an arithmetic number, because the mean of its divisors is an integer number (13879168).

Almost surely, 2^55082821 is an apocalyptic number.

It is an amenable number.

55082821 is a deficient number, since it is larger than the sum of its proper divisors (433851).

55082821 is a wasteful number, since it uses less digits than its factorization.

55082821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433850.

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 55082821 is about 7421.7801772890. The cubic root of 55082821 is about 380.4860378113.

The spelling of 55082821 in words is "fifty-five million, eighty-two thousand, eight hundred twenty-one".