2187997812 has 384 divisors, whose sum is σ = 7836487680. Its totient is φ = 509483520.

The previous prime is 2187997811. The next prime is 2187997813.

2187997812 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (2187997811) and next prime (2187997813).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2187997811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3999723 + ... + 4000269.

It is an arithmetic number, because the mean of its divisors is an integer number (20407520).

Almost surely, 2^2187997812 is an apocalyptic number.

2187997812 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2187997812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3918243840).

2187997812 is an abundant number, since it is smaller than the sum of its proper divisors (5648489868).

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

2187997812 is a wasteful number, since it uses less digits than its factorization.

2187997812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628 (or 620 counting only the distinct ones).

The product of its digits is 1016064, while the sum is 54.

The square root of 2187997812 is about 46776.0388660690. The cubic root of 2187997812 is about 1298.2219898367.

It can be divided in two parts, 2187 and 997812, that added together give a palindrome (999999).

The spelling of 2187997812 in words is "two billion, one hundred eighty-seven million, nine hundred ninety-seven thousand, eight hundred twelve".