21312210012120 has 256 divisors, whose sum is σ = 73297322496000. Its totient is φ = 5505440997888.

The previous prime is 21312210012103. The next prime is 21312210012127. The reversal of 21312210012120 is 2121001221312.

21312210012120 is a `hidden beast` number, since 2 + 1 + 312 + 210 + 0 + 121 + 20 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21312210012093 and 21312210012102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312210012127) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2165437 + ... + 6878483.

It is an arithmetic number, because the mean of its divisors is an integer number (286317666000).

Almost surely, 2^{21312210012120} is an apocalyptic number.

21312210012120 is a gapful number since it is divisible by the number (20) 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 21312210012120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36648661248000).

21312210012120 is an abundant number, since it is smaller than the sum of its proper divisors (51985112483880).

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

21312210012120 is a wasteful number, since it uses less digits than its factorization.

21312210012120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4713199 (or 4713189 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21312210012120 its reverse (2121001221312), we get a palindrome (23433211233432).

The spelling of 21312210012120 in words is "twenty-one trillion, three hundred twelve billion, two hundred ten million, twelve thousand, one hundred twenty".