21220131101220 has 144 divisors (see below), whose sum is σ = 64578579509808. Its totient is φ = 5640169835520.

The previous prime is 21220131101219. The next prime is 21220131101231. The reversal of 21220131101220 is 2210113102212.

21220131101220 is a `hidden beast` number, since 212 + 2 + 0 + 131 + 101 + 220 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 1680424801344 + 19539706299876 = 1296312^2 + 4420374^2 .

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 = 21220131101193 and 21220131101202.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 625189450 + ... + 625223390.

It is an arithmetic number, because the mean of its divisors is an integer number (448462357707).

Almost surely, 2^{21220131101220} is an apocalyptic number.

21220131101220 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 21220131101220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32289289754904).

21220131101220 is an abundant number, since it is smaller than the sum of its proper divisors (43358448408588).

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

21220131101220 is a wasteful number, since it uses less digits than its factorization.

21220131101220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45230 (or 45225 counting only the distinct ones).

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

Adding to 21220131101220 its reverse (2210113102212), we get a palindrome (23430244203432).

The spelling of 21220131101220 in words is "twenty-one trillion, two hundred twenty billion, one hundred thirty-one million, one hundred one thousand, two hundred twenty".