21312003120 has 80 divisors (see below), whose sum is σ = 66081246720. Its totient is φ = 5681993472.

The previous prime is 21312003019. The next prime is 21312003149. The reversal of 21312003120 is 2130021312.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21312003120.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2156751 + ... + 2166609.

It is an arithmetic number, because the mean of its divisors is an integer number (826015584).

Almost surely, 2^21312003120 is an apocalyptic number.

21312003120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312003120 is an abundant number, since it is smaller than the sum of its proper divisors (44769243600).

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

21312003120 is a wasteful number, since it uses less digits than its factorization.

21312003120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18882 (or 18876 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21312003120 its reverse (2130021312), we get a palindrome (23442024432).

The spelling of 21312003120 in words is "twenty-one billion, three hundred twelve million, three thousand, one hundred twenty".