1820408 has 16 divisors (see below), whose sum is σ = 3428880. Its totient is φ = 906048.

The previous prime is 1820407. The next prime is 1820419. The reversal of 1820408 is 8040281.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820407) 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 3 ways as a sum of consecutive naturals, for example, 2141 + ... + 2867.

It is an arithmetic number, because the mean of its divisors is an integer number (214305).

2^1820408 is an apocalyptic number.

It is an amenable number.

1820408 is a deficient number, since it is larger than the sum of its proper divisors (1608472).

1820408 is a wasteful number, since it uses less digits than its factorization.

1820408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046 (or 1042 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 1820408 is about 1349.2249627101. The cubic root of 1820408 is about 122.1020377196.

Adding to 1820408 its reverse (8040281), we get a palindrome (9860689).

The spelling of 1820408 in words is "one million, eight hundred twenty thousand, four hundred eight".