1821023 has 4 divisors (see below), whose sum is σ = 1928160. Its totient is φ = 1713888.

The previous prime is 1821019. The next prime is 1821037. The reversal of 1821023 is 3201281.

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

It is a cyclic number.

It is not a de Polignac number, because 1821023 - 2² = 1821019 is a prime.

It is a super-2 number, since 2×1821023² = 6632249533058, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 107119 = 1821023 / (1 + 8 + 2 + 1 + 0 + 2 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1820992 and 1821010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821013) 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, 53543 + ... + 53576.

It is an arithmetic number, because the mean of its divisors is an integer number (482040).

2^1821023 is an apocalyptic number.

1821023 is a deficient number, since it is larger than the sum of its proper divisors (107137).

1821023 is a wasteful number, since it uses less digits than its factorization.

1821023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107136.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1821023 is about 1349.4528520849. The cubic root of 1821023 is about 122.1157863405.

The spelling of 1821023 in words is "one million, eight hundred twenty-one thousand, twenty-three".