21312210020220 has 192 divisors, whose sum is σ = 75794671411200. Its totient is φ = 4870209991680.

The previous prime is 21312210020197. The next prime is 21312210020263. The reversal of 21312210020220 is 2202001221312.

21312210020220 is a `hidden beast` number, since 213 + 1 + 2 + 210 + 0 + 20 + 220 = 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 = 21312210020193 and 21312210020202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 15366261 + ... + 16695699.

It is an arithmetic number, because the mean of its divisors is an integer number (394763913600).

Almost surely, 2^{21312210020220} is an apocalyptic number.

21312210020220 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 21312210020220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37897335705600).

21312210020220 is an abundant number, since it is smaller than the sum of its proper divisors (54482461390980).

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

21312210020220 is a wasteful number, since it uses less digits than its factorization.

21312210020220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333705 (or 1333697 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21312210020220 its reverse (2202001221312), we get a palindrome (23514211241532).

The spelling of 21312210020220 in words is "twenty-one trillion, three hundred twelve billion, two hundred ten million, twenty thousand, two hundred twenty".