1821706 has 4 divisors (see below), whose sum is σ = 2732562. Its totient is φ = 910852.

The previous prime is 1821691. The next prime is 1821707. The reversal of 1821706 is 6071281.

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

It can be written as a sum of positive squares in only one way, i.e., 1418481 + 403225 = 1191^2 + 635^2 .

It is a super-2 number, since 2×1821706² = 6637225500872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1821707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 455425 + ... + 455428.

2^1821706 is an apocalyptic number.

1821706 is a deficient number, since it is larger than the sum of its proper divisors (910856).

1821706 is an equidigital number, since it uses as much as digits as its factorization.

1821706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910855.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 1821706 is about 1349.7058938895. The cubic root of 1821706 is about 122.1310515068.

Adding to 1821706 its reverse (6071281), we get a palindrome (7892987).

The spelling of 1821706 in words is "one million, eight hundred twenty-one thousand, seven hundred six".