21231110012220 has 48 divisors (see below), whose sum is σ = 66052342261920. Its totient is φ = 5661629336448.

The previous prime is 21231110012207. The next prime is 21231110012221. The reversal of 21231110012220 is 2221001113212.

21231110012220 is a `hidden beast` number, since 21 + 2 + 311 + 100 + 12 + 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 = 21231110012193 and 21231110012202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231110012221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19658434657 + ... + 19658435736.

It is an arithmetic number, because the mean of its divisors is an integer number (1376090463790).

Almost surely, 2^{21231110012220} is an apocalyptic number.

21231110012220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231110012220 is an abundant number, since it is smaller than the sum of its proper divisors (44821232249700).

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

21231110012220 is a wasteful number, since it uses less digits than its factorization.

21231110012220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39316870411 (or 39316870403 counting only the distinct ones).

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

Adding to 21231110012220 its reverse (2221001113212), we get a palindrome (23452111125432).

The spelling of 21231110012220 in words is "twenty-one trillion, two hundred thirty-one billion, one hundred ten million, twelve thousand, two hundred twenty".