21110401220 has 24 divisors (see below), whose sum is σ = 44339576064. Its totient is φ = 8442687456.

The previous prime is 21110401217. The next prime is 21110401241. The reversal of 21110401220 is 2210401112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21110401195 and 21110401204.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29357 + ... + 207563.

It is an arithmetic number, because the mean of its divisors is an integer number (1847482336).

Almost surely, 2^21110401220 is an apocalyptic number.

21110401220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110401220 is an abundant number, since it is smaller than the sum of its proper divisors (23229174844).

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

21110401220 is a wasteful number, since it uses less digits than its factorization.

21110401220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184139 (or 184137 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21110401220 its reverse (2210401112), we get a palindrome (23320802332).

The spelling of 21110401220 in words is "twenty-one billion, one hundred ten million, four hundred one thousand, two hundred twenty".