55328821 has 2 divisors, whose sum is σ = 55328822. Its totient is φ = 55328820.

The previous prime is 55328807. The next prime is 55328837. The reversal of 55328821 is 12882355.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28143025 + 27185796 = 5305^2 + 5214^2 .

It is a cyclic number.

It is not a de Polignac number, because 55328821 - 2⁵ = 55328789 is a prime.

It is a super-2 number, since 2×55328821² = 6122556866500082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55328851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27664410 + 27664411.

It is an arithmetic number, because the mean of its divisors is an integer number (27664411).

Almost surely, 2^55328821 is an apocalyptic number.

It is an amenable number.

55328821 is a deficient number, since it is larger than the sum of its proper divisors (1).

55328821 is an equidigital number, since it uses as much as digits as its factorization.

55328821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19200, while the sum is 34.

The square root of 55328821 is about 7438.3345582193. The cubic root of 55328821 is about 381.0516138516.

The spelling of 55328821 in words is "fifty-five million, three hundred twenty-eight thousand, eight hundred twenty-one".