2126821 has 4 divisors (see below), whose sum is σ = 2130732. Its totient is φ = 2122912.

The previous prime is 2126809. The next prime is 2126827. The reversal of 2126821 is 1286212.

2126821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1185921 + 940900 = 1089^2 + 970^2 .

It is a cyclic number.

It is not a de Polignac number, because 2126821 - 2¹³ = 2118629 is a prime.

It is a Duffinian number.

2126821 is a lucky number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 2126792 and 2126801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2126827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 976 + ... + 2281.

It is an arithmetic number, because the mean of its divisors is an integer number (532683).

2^2126821 is an apocalyptic number.

It is an amenable number.

2126821 is a deficient number, since it is larger than the sum of its proper divisors (3911).

2126821 is an equidigital number, since it uses as much as digits as its factorization.

2126821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3910.

The product of its digits is 384, while the sum is 22.

The square root of 2126821 is about 1458.3624378048. The cubic root of 2126821 is about 128.6007929990.

The spelling of 2126821 in words is "two million, one hundred twenty-six thousand, eight hundred twenty-one".