1821811120 has 40 divisors (see below), whose sum is σ = 4484873664. Its totient is φ = 685857792.

The previous prime is 1821811111. The next prime is 1821811129. The reversal of 1821811120 is 211181281.

It is an interprime number because it is at equal distance from previous prime (1821811111) and next prime (1821811129).

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (1821811129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 668424 + ... + 671143.

Almost surely, 2^1821811120 is an apocalyptic number.

1821811120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821811120 is an abundant number, since it is smaller than the sum of its proper divisors (2663062544).

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

1821811120 is a wasteful number, since it uses less digits than its factorization.

1821811120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1339597 (or 1339591 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 25.

The square root of 1821811120 is about 42682.6793910598. The cubic root of 1821811120 is about 1221.3340061791.

The spelling of 1821811120 in words is "one billion, eight hundred twenty-one million, eight hundred eleven thousand, one hundred twenty".