1821867 has 16 divisors (see below), whose sum is σ = 2576640. Its totient is φ = 1143072.

The previous prime is 1821857. The next prime is 1821871. The reversal of 1821867 is 7681281.

It is a happy number.

It is not a de Polignac number, because 1821867 - 2¹⁰ = 1820843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3498 + ... + 3984.

It is an arithmetic number, because the mean of its divisors is an integer number (161040).

2^1821867 is an apocalyptic number.

1821867 is a deficient number, since it is larger than the sum of its proper divisors (754773).

1821867 is a wasteful number, since it uses less digits than its factorization.

1821867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 562.

The product of its digits is 5376, while the sum is 33.

The square root of 1821867 is about 1349.7655351949. The cubic root of 1821867 is about 122.1346493285.

The spelling of 1821867 in words is "one million, eight hundred twenty-one thousand, eight hundred sixty-seven".