1821402 has 24 divisors (see below), whose sum is σ = 4305600. Its totient is φ = 551880.

The previous prime is 1821401. The next prime is 1821409. The reversal of 1821402 is 2041281.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (1821401) 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 11 ways as a sum of consecutive naturals, for example, 4402 + ... + 4797.

It is an arithmetic number, because the mean of its divisors is an integer number (179400).

2^1821402 is an apocalyptic number.

1821402 is an abundant number, since it is smaller than the sum of its proper divisors (2484198).

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

1821402 is a wasteful number, since it uses less digits than its factorization.

1821402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9218 (or 9215 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 1821402 is about 1349.5932720638. The cubic root of 1821402 is about 122.1242575263.

Adding to 1821402 its reverse (2041281), we get a palindrome (3862683).

The spelling of 1821402 in words is "one million, eight hundred twenty-one thousand, four hundred two".