21210312120 has 64 divisors (see below), whose sum is σ = 63662436000. Its totient is φ = 5653283328.

The previous prime is 21210312083. The next prime is 21210312181. The reversal of 21210312120 is 2121301212.

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 21210312120.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 205566 + ... + 290994.

Almost surely, 2^21210312120 is an apocalyptic number.

21210312120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210312120 is an abundant number, since it is smaller than the sum of its proper divisors (42452123880).

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

21210312120 is a wasteful number, since it uses less digits than its factorization.

21210312120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87512 (or 87508 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21210312120 its reverse (2121301212), we get a palindrome (23331613332).

The spelling of 21210312120 in words is "twenty-one billion, two hundred ten million, three hundred twelve thousand, one hundred twenty".