1821036 has 72 divisors (see below), whose sum is σ = 5234880. Its totient is φ = 489888.

The previous prime is 1821019. The next prime is 1821037. The reversal of 1821036 is 6301281.

It is a super-2 number, since 2×1821036² = 6632344226592, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (1821037) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11091 + ... + 11253.

2^1821036 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1821036, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2617440).

1821036 is an abundant number, since it is smaller than the sum of its proper divisors (3413844).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1821036 is a wasteful number, since it uses less digits than its factorization.

1821036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 1821036 is about 1349.4576688433. The cubic root of 1821036 is about 122.1160769284.

The spelling of 1821036 in words is "one million, eight hundred twenty-one thousand, thirty-six".