2061821 has 4 divisors (see below), whose sum is σ = 2088000. Its totient is φ = 2035644.

The previous prime is 2061793. The next prime is 2061847. The reversal of 2061821 is 1281602.

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.

It is a cyclic number.

It is not a de Polignac number, because 2061821 - 2⁶ = 2061757 is a prime.

It is a super-2 number, since 2×2061821² = 8502211672082, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2061793 and 2061802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2051821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12971 + ... + 13128.

It is an arithmetic number, because the mean of its divisors is an integer number (522000).

2^2061821 is an apocalyptic number.

It is an amenable number.

2061821 is a deficient number, since it is larger than the sum of its proper divisors (26179).

2061821 is an equidigital number, since it uses as much as digits as its factorization.

2061821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26178.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 2061821 is about 1435.9042447183. The cubic root of 2061821 is about 127.2771141190.

It can be divided in two parts, 2061 and 821, that added together give a palindrome (2882).

The spelling of 2061821 in words is "two million, sixty-one thousand, eight hundred twenty-one".