1821120003 has 14 divisors (see below), whose sum is σ = 2730432044. Its totient is φ = 1214079516.

The previous prime is 1821119987. The next prime is 1821120023. The reversal of 1821120003 is 3000211281.

It is not a de Polignac number, because 1821120003 - 2⁴ = 1821119987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821120023) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 1248325 + ... + 1249782.

Almost surely, 2^1821120003 is an apocalyptic number.

1821120003 is a deficient number, since it is larger than the sum of its proper divisors (909312041).

1821120003 is an frugal number, since it uses more digits than its factorization.

1821120003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2498125 (or 2498110 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 1821120003 is about 42674.5826341629. The cubic root of 1821120003 is about 1221.1795460662.

Adding to 1821120003 its reverse (3000211281), we get a palindrome (4821331284).

The spelling of 1821120003 in words is "one billion, eight hundred twenty-one million, one hundred twenty thousand, three".