1812121056 has 72 divisors (see below), whose sum is σ = 5377291920. Its totient is φ = 577775616.

The previous prime is 1812121013. The next prime is 1812121063. The reversal of 1812121056 is 6501212181.

It is a tau number, because it is divible by the number of its divisors (72).

It is an alternating number because its digits alternate between odd and even.

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, 130161 + ... + 143408.

It is an arithmetic number, because the mean of its divisors is an integer number (74684610).

Almost surely, 2^1812121056 is an apocalyptic number.

1812121056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1812121056 is an abundant number, since it is smaller than the sum of its proper divisors (3565170864).

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

1812121056 is a wasteful number, since it uses less digits than its factorization.

1812121056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273608 (or 273597 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 27.

The square root of 1812121056 is about 42569.0152105965. The cubic root of 1812121056 is about 1219.1647637945.

The spelling of 1812121056 in words is "one billion, eight hundred twelve million, one hundred twenty-one thousand, fifty-six".