1812661312 has 252 divisors, whose sum is σ = 4887106812. Its totient is φ = 662323200.

The previous prime is 1812661297. The next prime is 1812661337. The reversal of 1812661312 is 2131662181.

It can be written as a sum of positive squares in 2 ways, for example, as 1320886336 + 491774976 = 36344^2 + 22176^2 .

It is a super-2 number, since 2×1812661312² = 6571482064043122688, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 6450612 + ... + 6450892.

It is an arithmetic number, because the mean of its divisors is an integer number (19393281).

Almost surely, 2^1812661312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1812661312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2443553406).

1812661312 is an abundant number, since it is smaller than the sum of its proper divisors (3074445500).

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

1812661312 is a wasteful number, since it uses less digits than its factorization.

1812661312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346 (or 318 counting only the distinct ones).

The product of its digits is 3456, while the sum is 31.

The square root of 1812661312 is about 42575.3603860261. The cubic root of 1812661312 is about 1219.2859101588.

The spelling of 1812661312 in words is "one billion, eight hundred twelve million, six hundred sixty-one thousand, three hundred twelve".