2047821 has 4 divisors (see below), whose sum is σ = 2730432. Its totient is φ = 1365212.

The previous prime is 2047819. The next prime is 2047841. The reversal of 2047821 is 1287402.

2047821 = 473² + 474² + ... + 481².

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 2047821 - 2¹ = 2047819 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 2047791 and 2047800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2047811) 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, 341301 + ... + 341306.

It is an arithmetic number, because the mean of its divisors is an integer number (682608).

2^2047821 is an apocalyptic number.

It is an amenable number.

2047821 is a deficient number, since it is larger than the sum of its proper divisors (682611).

2047821 is an equidigital number, since it uses as much as digits as its factorization.

2047821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 682610.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 2047821 is about 1431.0209642070. The cubic root of 2047821 is about 126.9883842477.

The spelling of 2047821 in words is "two million, forty-seven thousand, eight hundred twenty-one".