2121312312 has 144 divisors (see below), whose sum is σ = 6706524240. Its totient is φ = 605743488.

The previous prime is 2121312311. The next prime is 2121312313. The reversal of 2121312312 is 2132131212.

2121312312 is a `hidden beast` number, since 21 + 21 + 312 + 312 = 666.

It is an interprime number because it is at equal distance from previous prime (2121312311) and next prime (2121312313).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121312311) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1209228 + ... + 1210980.

It is an arithmetic number, because the mean of its divisors is an integer number (46573085).

Almost surely, 2^2121312312 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 2121312312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3353262120).

2121312312 is an abundant number, since it is smaller than the sum of its proper divisors (4585211928).

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

2121312312 is an equidigital number, since it uses as much as digits as its factorization.

2121312312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800 (or 1765 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 2121312312 is about 46057.7063258691. The cubic root of 2121312312 is about 1284.8966718330.

Adding to 2121312312 its reverse (2132131212), we get a palindrome (4253443524).

The spelling of 2121312312 in words is "two billion, one hundred twenty-one million, three hundred twelve thousand, three hundred twelve".