1821900 has 36 divisors (see below), whose sum is σ = 5272232. Its totient is φ = 485760.

The previous prime is 1821893. The next prime is 1821913. The reversal of 1821900 is 91281.

It is a super-2 number, since 2×1821900² = 6638639220000, which contains 22 as substring.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2737 + ... + 3336.

2^1821900 is an apocalyptic number.

1821900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821900 is an abundant number, since it is smaller than the sum of its proper divisors (3450332).

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

1821900 is a wasteful number, since it uses less digits than its factorization.

1821900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6090 (or 6083 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 21.

The square root of 1821900 is about 1349.7777594849. Note that the first 4 decimals coincide. The cubic root of 1821900 is about 122.1353867441.

The spelling of 1821900 in words is "one million, eight hundred twenty-one thousand, nine hundred".