21001112112220 has 48 divisors (see below), whose sum is σ = 44720063539200. Its totient is φ = 8283065544000.

The previous prime is 21001112112209. The next prime is 21001112112263. The reversal of 21001112112220 is 2221121110012.

It is a junction number, because it is equal to n+sod(n) for n = 21001112112194 and 21001112112203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7662850 + ... + 10036009.

It is an arithmetic number, because the mean of its divisors is an integer number (931667990400).

Almost surely, 2^{21001112112220} is an apocalyptic number.

21001112112220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001112112220 is an abundant number, since it is smaller than the sum of its proper divisors (23718951426980).

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

21001112112220 is a wasteful number, since it uses less digits than its factorization.

21001112112220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17699698 (or 17699696 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21001112112220 its reverse (2221121110012), we get a palindrome (23222233222232).

The spelling of 21001112112220 in words is "twenty-one trillion, one billion, one hundred twelve million, one hundred twelve thousand, two hundred twenty".