1821716 has 24 divisors (see below), whose sum is σ = 3503304. Its totient is φ = 823680.

The previous prime is 1821713. The next prime is 1821731. The reversal of 1821716 is 6171281.

It can be written as a sum of positive squares in 4 ways, for example, as 372100 + 1449616 = 610^2 + 1204^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821713) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2426 + ... + 3086.

It is an arithmetic number, because the mean of its divisors is an integer number (145971).

2^1821716 is an apocalyptic number.

It is an amenable number.

1821716 is a deficient number, since it is larger than the sum of its proper divisors (1681588).

1821716 is a wasteful number, since it uses less digits than its factorization.

1821716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731 (or 729 counting only the distinct ones).

The product of its digits is 672, while the sum is 26.

The square root of 1821716 is about 1349.7095983952. The cubic root of 1821716 is about 122.1312749802.

Adding to 1821716 its reverse (6171281), we get a palindrome (7992997).

The spelling of 1821716 in words is "one million, eight hundred twenty-one thousand, seven hundred sixteen".