21011112122220 has 192 divisors, whose sum is σ = 72479466017280. Its totient is φ = 5010101164800.

The previous prime is 21011112122201. The next prime is 21011112122261. The reversal of 21011112122220 is 2222121111012.

21011112122220 is a `hidden beast` number, since 210 + 1 + 1 + 112 + 122 + 220 = 666.

It is a super-2 number, since 2×21011112122220² (a number of 27 digits) contains 22 as substring.

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 = 21011112122193 and 21011112122202.

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, 28631302 + ... + 29355981.

It is an arithmetic number, because the mean of its divisors is an integer number (377497218840).

Almost surely, 2^{21011112122220} is an apocalyptic number.

21011112122220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011112122220 is an abundant number, since it is smaller than the sum of its proper divisors (51468353895060).

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

21011112122220 is a wasteful number, since it uses less digits than its factorization.

21011112122220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57987373 (or 57987365 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21011112122220 its reverse (2222121111012), we get a palindrome (23233233233232).

The spelling of 21011112122220 in words is "twenty-one trillion, eleven billion, one hundred twelve million, one hundred twenty-two thousand, two hundred twenty".