1818472821 has 24 divisors (see below), whose sum is σ = 2669724960. Its totient is φ = 1100188320.

The previous prime is 1818472787. The next prime is 1818472823. The reversal of 1818472821 is 1282748181.

It is not a de Polignac number, because 1818472821 - 2⁶ = 1818472757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1818472823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 220651 + ... + 228743.

It is an arithmetic number, because the mean of its divisors is an integer number (111238540).

Almost surely, 2^1818472821 is an apocalyptic number.

1818472821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1818472821 is a deficient number, since it is larger than the sum of its proper divisors (851252139).

1818472821 is a wasteful number, since it uses less digits than its factorization.

1818472821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8737 (or 8726 counting only the distinct ones).

The product of its digits is 57344, while the sum is 42.

The square root of 1818472821 is about 42643.5554451080. Note that the first 3 decimals coincide. The cubic root of 1818472821 is about 1220.5875564997.

The spelling of 1818472821 in words is "one billion, eight hundred eighteen million, four hundred seventy-two thousand, eight hundred twenty-one".