2055821 has 2 divisors, whose sum is σ = 2055822. Its totient is φ = 2055820.

The previous prime is 2055769. The next prime is 2055829. The reversal of 2055821 is 1285502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1974025 + 81796 = 1405^2 + 286^2 .

It is a cyclic number.

It is not a de Polignac number, because 2055821 - 2¹⁴ = 2039437 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p₁₅₂₇₈₀ and since 2055821 and 152780 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2055829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1027910 + 1027911.

It is an arithmetic number, because the mean of its divisors is an integer number (1027911).

2^2055821 is an apocalyptic number.

It is an amenable number.

2055821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2055821 is an equidigital number, since it uses as much as digits as its factorization.

2055821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 2055821 is about 1433.8134467217. The cubic root of 2055821 is about 127.1535332893.

The spelling of 2055821 in words is "two million, fifty-five thousand, eight hundred twenty-one".